diff --git a/src/Autopilot/auto_gui.cxx b/src/Autopilot/auto_gui.cxx
index 585689094..b148bd908 100644
--- a/src/Autopilot/auto_gui.cxx
+++ b/src/Autopilot/auto_gui.cxx
@@ -28,6 +28,8 @@
 
 #include <simgear/compiler.h>
 
+#include <simgear/route/route.hxx>
+
 #include <assert.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/src/Autopilot/newauto.cxx b/src/Autopilot/newauto.cxx
index fb9a37814..83e601fc6 100644
--- a/src/Autopilot/newauto.cxx
+++ b/src/Autopilot/newauto.cxx
@@ -34,6 +34,7 @@
 #include <simgear/debug/logstream.hxx>
 #include <simgear/math/sg_geodesy.hxx>
 #include <simgear/math/sg_random.h>
+#include <simgear/route/route.hxx>
 
 #include <Cockpit/steam.hxx>
 #include <Cockpit/radiostack.hxx>
diff --git a/src/Cockpit/cockpit.cxx b/src/Cockpit/cockpit.cxx
index 6feb75bb3..fa2780343 100644
--- a/src/Cockpit/cockpit.cxx
+++ b/src/Cockpit/cockpit.cxx
@@ -39,6 +39,7 @@
 #include <simgear/debug/logstream.hxx>
 #include <simgear/math/polar3d.hxx>
 #include <simgear/misc/props.hxx>
+#include <simgear/timing/sg_time.hxx>
 
 #include <Aircraft/aircraft.hxx>
 #include <Include/general.hxx>
diff --git a/src/Cockpit/hud.cxx b/src/Cockpit/hud.cxx
index fb7c29d1c..098e755c7 100644
--- a/src/Cockpit/hud.cxx
+++ b/src/Cockpit/hud.cxx
@@ -45,6 +45,7 @@
 #include <simgear/constants.h>
 #include <simgear/debug/logstream.hxx>
 #include <simgear/misc/props.hxx>
+#include <simgear/misc/sg_path.hxx>
 //#include <simgear/math/fg_random.h>
 //#include <simgear/math/polar3d.hxx>
 
diff --git a/src/FDM/flight.cxx b/src/FDM/flight.cxx
index 22870b3bd..991e150dd 100644
--- a/src/FDM/flight.cxx
+++ b/src/FDM/flight.cxx
@@ -407,7 +407,7 @@ FGInterface::unbind ()
 void
 FGInterface::update (int dt)
 {
-    cout << "dummy update() ... SHOULDN'T BE CALLED!" << endl;
+    SG_LOG(SG_FLIGHT, SG_ALERT, "dummy update() ... SHOULDN'T BE CALLED!");
 }
 
 
@@ -525,7 +525,7 @@ void FGInterface::extrapolate( int time_offset ) {
     // -dw- metrowerks complains about ambiguous access, not critical
     // to keep this ;)
 #ifndef __MWERKS__
-    cout << "extrapolating FDM by dt = " << dt << endl;
+    SG_LOG(SG_FLIGHT, SG_INFO, "extrapolating FDM by dt = " << dt);
 #endif
 
     double lat = geodetic_position_v[0] + geocentric_rates_v[0] * dt;
diff --git a/src/GUI/prop_picker.cxx b/src/GUI/prop_picker.cxx
index a7e5c6c07..83e90005c 100755
--- a/src/GUI/prop_picker.cxx
+++ b/src/GUI/prop_picker.cxx
@@ -39,6 +39,7 @@
 #include <Main/globals.hxx>
 
 #include <simgear/compiler.h>
+#include <simgear/misc/props.hxx>
 
 #define DOTDOTSLASH "../"
 #define SLASH       "/"
diff --git a/src/Main/fg_io.cxx b/src/Main/fg_io.cxx
index 5e22ce66a..9bfff40d2 100644
--- a/src/Main/fg_io.cxx
+++ b/src/Main/fg_io.cxx
@@ -90,7 +90,7 @@ static FGProtocol *parse_port_config( const string& config )
 	FGATC610x *atc610x = new FGATC610x;
 	io = atc610x;
         short_circuit = true;
-	cout << "here ..." << endl;
+	std::cout << "here ..." << endl;
     } else if ( protocol == "atlas" ) {
 	FGAtlas *atlas = new FGAtlas;
 	io = atlas;
@@ -299,7 +299,7 @@ void fgIOProcess() {
 	    p->dec_count_down( interval );
 	    while ( p->get_count_down() < 0 ) {
 		p->process();
-		p->dec_count_down( -1000000.0 / p->get_hz() );
+		p->dec_count_down(int( -1000000.0 / p->get_hz()));
 	    }
 	}
     }
diff --git a/src/Main/fg_props.cxx b/src/Main/fg_props.cxx
index ebbc4bc87..4d42d8c08 100644
--- a/src/Main/fg_props.cxx
+++ b/src/Main/fg_props.cxx
@@ -25,6 +25,8 @@
 #endif
 
 #include <simgear/misc/exception.hxx>
+#include <simgear/magvar/magvar.hxx>
+#include <simgear/timing/sg_time.hxx>
 
 #include STL_IOSTREAM
 
diff --git a/src/Main/fg_props.hxx b/src/Main/fg_props.hxx
index 3a612cdb2..e53cc3bf4 100644
--- a/src/Main/fg_props.hxx
+++ b/src/Main/fg_props.hxx
@@ -8,6 +8,8 @@
 
 #include <simgear/debug/logstream.hxx>
 #include <simgear/misc/props.hxx>
+#include <simgear/misc/props_io.hxx>
+
 #include "globals.hxx"
 
 
diff --git a/src/Main/globals.cxx b/src/Main/globals.cxx
index 1540d7a61..15c898998 100644
--- a/src/Main/globals.cxx
+++ b/src/Main/globals.cxx
@@ -21,6 +21,8 @@
 // $Id$
 
 
+#include <simgear/misc/commands.hxx>
+
 #include <Environment/environment_mgr.hxx>
 
 #include "globals.hxx"
diff --git a/src/Main/globals.hxx b/src/Main/globals.hxx
index 52d58e451..75c119313 100644
--- a/src/Main/globals.hxx
+++ b/src/Main/globals.hxx
@@ -29,14 +29,6 @@
 #include <vector>
 #include STL_STRING
 
-
-#include <simgear/ephemeris/ephemeris.hxx>
-#include <simgear/magvar/magvar.hxx>
-#include <simgear/route/route.hxx>
-#include <simgear/timing/sg_time.hxx>
-#include <simgear/misc/commands.hxx>
-#include <simgear/misc/props.hxx>
-
 #include "viewmgr.hxx"
 
 SG_USING_STD( vector );
@@ -46,6 +38,22 @@ typedef vector<string> string_list;
 
 
 // Forward declarations
+
+// This file is included, directly or indirectly, almost everywhere in
+// FlightGear, so if any of its dependencies changes, most of the sim
+// has to be recompiled.  Using these forward declarations helps us to
+// avoid including a lot of header files (and thus, a lot of
+// dependencies).  Since Most of the methods simply set or return
+// pointers, we don't need to know anything about the class details
+// anyway.
+
+class SGEphemeris;
+class SGMagVar;
+class SGRoute;
+class SGTime;
+class SGPropertyNode;
+class SGCommandMgr;
+
 class FGLogger;
 class FGEnvironmentMgr;
 class FGEnvironment;
@@ -57,7 +65,12 @@ class FGViewer;
 class FGATCMgr;
 class FGATCDisplay;
 
-class FGGlobals {
+
+/**
+ * Bucket for subsystem pointers representing the sim's state.
+ */
+class FGGlobals
+{
 
 private:
 
diff --git a/src/Main/main.cxx b/src/Main/main.cxx
index e0aa6d70b..1a350a6f7 100644
--- a/src/Main/main.cxx
+++ b/src/Main/main.cxx
@@ -32,6 +32,8 @@
 
 #include <simgear/compiler.h>
 #include <simgear/misc/exception.hxx>
+#include <simgear/ephemeris/ephemeris.hxx>
+#include <simgear/route/route.hxx>
 
 #ifdef SG_MATH_EXCEPTION_CLASH
 #  include <math.h>
diff --git a/src/Main/options.cxx b/src/Main/options.cxx
index 52e3f7748..2b0122f2e 100644
--- a/src/Main/options.cxx
+++ b/src/Main/options.cxx
@@ -36,6 +36,9 @@
 #include STL_STRING
 
 #include <simgear/misc/sgstream.hxx>
+#include <simgear/misc/sg_path.hxx>
+#include <simgear/route/route.hxx>
+#include <simgear/route/waypoint.hxx>
 
 // #include <Include/general.hxx>
 // #include <Airports/simple.hxx>
diff --git a/src/Network/garmin.cxx b/src/Network/garmin.cxx
index 45e03c66c..877baca1b 100644
--- a/src/Network/garmin.cxx
+++ b/src/Network/garmin.cxx
@@ -24,6 +24,7 @@
 #include <simgear/debug/logstream.hxx>
 #include <simgear/math/sg_geodesy.hxx>
 #include <simgear/io/iochannel.hxx>
+#include <simgear/timing/sg_time.hxx>
 
 #include <FDM/flight.hxx>
 #include <Main/globals.hxx>
@@ -144,7 +145,7 @@ bool FGGarmin::gen_message() {
     garmin_sentence += rmz_sum;
     garmin_sentence += "\n";
 
-    cout << garmin_sentence;
+    std::cout << garmin_sentence;
 
     length = garmin_sentence.length();
     strncpy( buf, garmin_sentence.c_str(), length );
diff --git a/src/Network/native_fdm.cxx b/src/Network/native_fdm.cxx
index 33566a9d8..9f83f4fab 100644
--- a/src/Network/native_fdm.cxx
+++ b/src/Network/native_fdm.cxx
@@ -28,6 +28,7 @@
 #include <simgear/debug/logstream.hxx>
 #include <simgear/io/lowlevel.hxx> // endian tests
 #include <simgear/io/iochannel.hxx>
+#include <simgear/timing/sg_time.hxx>
 
 #include <FDM/flight.hxx>
 #include <Time/tmp.hxx>
diff --git a/src/Network/nmea.cxx b/src/Network/nmea.cxx
index d6c9726e1..8bb63ee41 100644
--- a/src/Network/nmea.cxx
+++ b/src/Network/nmea.cxx
@@ -24,6 +24,7 @@
 #include <simgear/debug/logstream.hxx>
 #include <simgear/math/sg_geodesy.hxx>
 #include <simgear/io/iochannel.hxx>
+#include <simgear/timing/sg_time.hxx>
 
 #include <FDM/flight.hxx>
 #include <Main/globals.hxx>
@@ -144,7 +145,7 @@ bool FGNMEA::gen_message() {
     nmea_sentence += gga_sum;
     nmea_sentence += "\n";
 
-    cout << nmea_sentence;
+    std::cout << nmea_sentence;
 
     length = nmea_sentence.length();
     strncpy( buf, nmea_sentence.c_str(), length );
diff --git a/src/Network/props.cxx b/src/Network/props.cxx
index 5cdd5c0a4..bb5c5e57a 100644
--- a/src/Network/props.cxx
+++ b/src/Network/props.cxx
@@ -21,13 +21,15 @@
 // $Id$
 
 
-#include <Main/globals.hxx>
 
 #include <simgear/compiler.h>
 #include <simgear/debug/logstream.hxx>
 #include <simgear/io/iochannel.hxx>
 #include <simgear/math/sg_types.hxx>
 #include <simgear/misc/props.hxx>
+#include <simgear/misc/props_io.hxx>
+
+#include <Main/globals.hxx>
 
 #include <stdlib.h>		// atoi() atof()
 
@@ -38,6 +40,7 @@
 #if !defined(SG_HAVE_NATIVE_SGI_COMPILERS)
 SG_USING_STD(cout);
 SG_USING_STD(istrstream);
+SG_USING_STD(strstream);
 #endif
 
 FGProps::FGProps() {
diff --git a/src/NetworkOLK/network.cxx b/src/NetworkOLK/network.cxx
index d145ed5ab..ce4e1bbf3 100644
--- a/src/NetworkOLK/network.cxx
+++ b/src/NetworkOLK/network.cxx
@@ -63,6 +63,8 @@ extern "C" {
 #include <plib/sg.h>
 #include <plib/ssg.h>
 
+#include <simgear/compiler.h>
+
 #include <Main/globals.hxx>
 #include <Main/fg_props.hxx>
 
diff --git a/src/Objects/matlib.cxx b/src/Objects/matlib.cxx
index 15a045fb8..272c23fc3 100644
--- a/src/Objects/matlib.cxx
+++ b/src/Objects/matlib.cxx
@@ -71,7 +71,7 @@ bool FGMaterialLib::load( const string& mpath ) {
 
   SGPropertyNode materials;
 
-  cout << "Reading materials from " << mpath << endl;
+  SG_LOG(SG_INPUT, SG_INFO, "Reading materials from " << mpath);
   try {
     readProperties(mpath, &materials);
   } catch (const sg_exception &ex) {
diff --git a/src/Objects/obj.cxx b/src/Objects/obj.cxx
index f2470c5db..6b273074b 100644
--- a/src/Objects/obj.cxx
+++ b/src/Objects/obj.cxx
@@ -478,10 +478,8 @@ ssgBranch *fgAsciiObjLoad( const string& path, FGTileEntry *t,
 		    string file = path;
 		    int pos = file.rfind( "/" );
 		    file = file.substr( 0, pos );
-		    cout << "current file = " << file << endl;
 		    file += "/";
 		    file += material;
-		    cout << "current file = " << file << endl;
 		    if ( ! material_lib.add_item( file ) ) {
 			SG_LOG( SG_TERRAIN, SG_ALERT, 
 				"Ack! unknown usemtl name = " << material 
@@ -504,8 +502,6 @@ ssgBranch *fgAsciiObjLoad( const string& path, FGTileEntry *t,
 		    tex_height = newmat->get_ysize();
 		    state = newmat->get_state();
 		    coverage = newmat->get_light_coverage();
-		    // cout << "(w) = " << tex_width << " (h) = " 
-		    //      << tex_width << endl;
 		} else {
 		    coverage = -1;
 		}
@@ -520,8 +516,6 @@ ssgBranch *fgAsciiObjLoad( const string& path, FGTileEntry *t,
 	
 	    in >> token;
 
-	    // cout << "token = " << token << endl;
-
 	    if ( token == "vn" ) {
 		// vertex normal
 		if ( vncount < FG_MAX_NODES ) {
@@ -634,10 +628,6 @@ ssgBranch *fgAsciiObjLoad( const string& path, FGTileEntry *t,
 
 		    in >> n3;
 		    fan_vertices.push_back( n3 );
-		    // cout << "  triangle = " 
-		    //      << n1 << "," << n2 << "," << n3 
-		    //      << endl;
-		    // xglNormal3dv(normals[n3]);
 		    if ( in.get( c ) && c == '/' ) {
 			in >> tex;
 			fan_tex_coords.push_back( tex );
@@ -767,10 +757,8 @@ ssgLeaf *gen_leaf( const string& path,
 	string file = path;
 	int pos = file.rfind( "/" );
 	file = file.substr( 0, pos );
-	cout << "current file = " << file << endl;
 	file += "/";
 	file += material;
-	cout << "current file = " << file << endl;
 	if ( ! material_lib.add_item( file ) ) {
 	    SG_LOG( SG_TERRAIN, SG_ALERT, 
 		    "Ack! unknown usemtl name = " << material 
@@ -793,19 +781,10 @@ ssgLeaf *gen_leaf( const string& path,
 	tex_height = newmat->get_ysize();
 	state = newmat->get_state();
 	coverage = newmat->get_light_coverage();
-	// cout << "(w) = " << tex_width << " (h) = " 
-	//      << tex_width << endl;
     } else {
 	coverage = -1;
     }
 
-    // cout << "before list allocs" << endl;
-
-    // cout << "before vl, size = " << size << endl;
-    // cout << "before nl" << endl;
-    // cout << "before tl" << endl;
-    // cout << "before cl" << endl;
-
     sgVec2 tmp2;
     sgVec3 tmp3;
     sgVec4 tmp4;
@@ -879,14 +858,9 @@ ssgLeaf *gen_leaf( const string& path,
         }
     }
 
-    // cout << "before leaf create" << endl;
     ssgLeaf *leaf = new ssgVtxTable ( ty, vl, nl, tl, cl );
-    // cout << "after leaf create" << endl;
 
     // lookup the state record
-    // cout << "looking up material = " << endl;
-    // cout << material << endl;
-    // cout << "'" << endl;
 
     leaf->setState( state );
 
@@ -919,9 +893,6 @@ bool fgBinObjLoad( const string& path, const bool is_base,
 	return false;
     }
 
-    // cout << "fans size = " << obj.get_fans_v().size()
-    //      << " fan_mats size = " << obj.get_fan_materials().size() << endl;
-
     geometry->setName( (char *)path.c_str() );
    
     if ( is_base ) {
@@ -948,7 +919,6 @@ bool fgBinObjLoad( const string& path, const bool is_base,
     group_list pts_v = obj.get_pts_v();
     group_list pts_n = obj.get_pts_n();
     for ( i = 0; i < (int)pts_v.size(); ++i ) {
-        cout << "pts_v.size() = " << pts_v.size() << endl;
 	tmp_mat = pt_materials[i];
 	if ( tmp_mat.substr(0, 3) == "RWY" ) {
 	    material = "LIGHTS";
diff --git a/src/Scenery/FGTileLoader.cxx b/src/Scenery/FGTileLoader.cxx
index 07ab84080..2e0a01b2b 100644
--- a/src/Scenery/FGTileLoader.cxx
+++ b/src/Scenery/FGTileLoader.cxx
@@ -24,6 +24,8 @@
 #  include <config.h>
 #endif
 
+#include <simgear/compiler.h>
+
 #include <Main/globals.hxx>
 #include "FGTileLoader.hxx"
 #include "tileentry.hxx"
diff --git a/src/Scenery/tilemgr.cxx b/src/Scenery/tilemgr.cxx
index 4b6cffc74..bf2bcf869 100644
--- a/src/Scenery/tilemgr.cxx
+++ b/src/Scenery/tilemgr.cxx
@@ -292,7 +292,6 @@ int FGTileMgr::update( double lon, double lat ) {
     // happen in the render thread because model loading can trigger
     // texture loading which involves use of the opengl api.
     if ( !model_queue.empty() ) {
-        cout << "loading next model ..." << endl;
         // load the next tile in the queue
 #ifdef ENABLE_THREADS
 	FGDeferredModel* dm = model_queue.pop();
@@ -312,8 +311,6 @@ int FGTileMgr::update( double lon, double lat ) {
 	delete dm;
     }
 
-    // cout << "current elevation (ssg) == " << scenery.get_cur_elev() << endl;
-
     previous_bucket = current_bucket;
     last_longitude = longitude;
     last_latitude  = latitude;
@@ -337,7 +334,6 @@ int FGTileMgr::update( double lon, double lat ) {
 	e->add_ssg_nodes( terrain_branch,
 			  gnd_lights_branch,
 			  rwy_lights_branch );
-	// cout << "Adding ssg nodes for "
     }
 
     sgdVec3 sc;
@@ -349,7 +345,6 @@ int FGTileMgr::update( double lon, double lat ) {
 #if 0
     if ( scenery.center == Point3D(0.0) ) {
 	// initializing
-	cout << "initializing scenery current elevation ... " << endl;
 	sgdVec3 tmp_abs_view_pos;
 
 	Point3D geod_pos = Point3D( longitude * SGD_DEGREES_TO_RADIANS,
@@ -359,7 +354,6 @@ int FGTileMgr::update( double lon, double lat ) {
 	scenery.center = tmp;
 	sgdSetVec3( tmp_abs_view_pos, tmp.x(), tmp.y(), tmp.z() );
 
-	// cout << "abs_view_pos = " << tmp_abs_view_pos << endl;
 	prep_ssg_nodes();
 
 	double tmp_elev;
@@ -370,24 +364,8 @@ int FGTileMgr::update( double lon, double lat ) {
 	} else {
 	    scenery.set_cur_elev( 0.0 );
 	}
-	cout << "result = " << scenery.get_cur_elev() << endl;
     } else {
 #endif
-        /*
-	cout << "abs view pos = "
-             << globals->get_current_view()->get_abs_view_pos()[0] << ","
-             << globals->get_current_view()->get_abs_view_pos()[1] << ","
-             << globals->get_current_view()->get_abs_view_pos()[2]
-	     << " view pos = " 
-             << globals->get_current_view()->get_view_pos()[0] << ","
-             << globals->get_current_view()->get_view_pos()[1] << ","
-             << globals->get_current_view()->get_view_pos()[2]
-             << endl;
-        cout << "current_tile = " << current_tile << endl;
-        cout << "Scenery center = " << sc[0] << "," << sc[1] << "," << sc[2]
-             << endl;
-        */
-
         // overridden with actual values if a terrain intersection is
         // found
 	double hit_elev = -9999.0;
@@ -415,8 +393,6 @@ int FGTileMgr::update( double lon, double lat ) {
             scenery.set_cur_radius( 0.0 );
             scenery.set_cur_normal( hit_normal );
         }
-
-	// cout << "Current elevation = " << scenery.get_cur_elev() << endl;
 #if 0
     }
 #endif
@@ -437,11 +413,10 @@ void FGTileMgr::prep_ssg_nodes() {
     tile_cache.reset_traversal();
 
     while ( ! tile_cache.at_end() ) {
-        // cout << "processing a tile" << endl;
         if ( (e = tile_cache.get_current()) ) {
 	    e->prep_ssg_node( scenery.get_center(), vis);
         } else {
-            cout << "warning ... empty tile in cache" << endl;
+	    SG_LOG(SG_INPUT, SG_ALERT, "warning ... empty tile in cache");
         }
 	tile_cache.next();
    }
diff --git a/src/Time/moonpos.cxx b/src/Time/moonpos.cxx
index 1818cdd53..a3bb711df 100644
--- a/src/Time/moonpos.cxx
+++ b/src/Time/moonpos.cxx
@@ -59,6 +59,7 @@
 #include <simgear/math/polar3d.hxx>
 #include <simgear/math/sg_geodesy.hxx>
 #include <simgear/math/vector.hxx>
+#include <simgear/timing/sg_time.hxx>
 
 #include <Main/globals.hxx>
 #include <Main/viewer.hxx>
diff --git a/src/Time/sunpos.cxx b/src/Time/sunpos.cxx
index c436b1b7d..1fff609cf 100644
--- a/src/Time/sunpos.cxx
+++ b/src/Time/sunpos.cxx
@@ -60,6 +60,7 @@
 #include <simgear/math/polar3d.hxx>
 #include <simgear/math/sg_geodesy.hxx>
 #include <simgear/math/vector.hxx>
+#include <simgear/timing/sg_time.hxx>
 
 #include <Main/globals.hxx>
 #include <Main/viewer.hxx>
diff --git a/src/Time/tmp.cxx b/src/Time/tmp.cxx
index b15514934..806c659ed 100644
--- a/src/Time/tmp.cxx
+++ b/src/Time/tmp.cxx
@@ -27,6 +27,7 @@
 
 #include <simgear/misc/sg_path.hxx>
 #include <simgear/magvar/magvar.hxx>
+#include <simgear/timing/sg_time.hxx>
 
 #include <FDM/flight.hxx>
 #include <Main/fg_props.hxx>
@@ -48,11 +49,11 @@ void fgUpdateLocalTime() {
     SGPath zone( globals->get_fg_root() );
     zone.append( "Timezone" );
 
-    cout << "updateLocal("
-         << longitude->getDoubleValue() * SGD_DEGREES_TO_RADIANS
-         << ", "
-         << latitude->getDoubleValue() * SGD_DEGREES_TO_RADIANS
-         << ", " << zone.str() << ")" << endl;
+    SG_LOG(SG_GENERAL, SG_INFO, "updateLocal("
+	   << longitude->getDoubleValue() * SGD_DEGREES_TO_RADIANS
+	   << ", "
+	   << latitude->getDoubleValue() * SGD_DEGREES_TO_RADIANS
+	   << ", " << zone.str() << ")");
     globals->get_time_params()->updateLocal( longitude->getDoubleValue()
 					       * SGD_DEGREES_TO_RADIANS, 
 					     latitude->getDoubleValue()