diff --git a/src/Autopilot/auto_gui.cxx b/src/Autopilot/auto_gui.cxx
index caa3bccc9..ed57b2863 100644
--- a/src/Autopilot/auto_gui.cxx
+++ b/src/Autopilot/auto_gui.cxx
@@ -315,7 +315,7 @@ void NewAltitudeInit()
 
     float alt = cur_fdm_state->get_Altitude();
 
-    if ( fgGetString("/sim/startup/units") == "meters") {
+    if ( !strcmp("/sim/startup/units", "meters")) {
 	alt *= SG_FEET_TO_METER;
     }
 
@@ -614,7 +614,7 @@ void TgtAptDialog_OK (puObject *)
 	TgtAptId = tmp.substr( 0, pos );
 	string alt_str = tmp.substr( pos + 1 );
 	alt = atof( alt_str.c_str() );
-	if ( fgGetString("/sim/startup/units") == "feet" ) {
+	if ( !strcmp("/sim/startup/units", "feet") ) {
 	    alt *= SG_FEET_TO_METER;
 	}
     } else {
diff --git a/src/Autopilot/newauto.cxx b/src/Autopilot/newauto.cxx
index a142a4874..95324fb38 100644
--- a/src/Autopilot/newauto.cxx
+++ b/src/Autopilot/newauto.cxx
@@ -28,6 +28,7 @@
 #endif
 
 #include <stdio.h>		// sprintf()
+#include <string.h>		// strcmp()
 
 #include <simgear/constants.h>
 #include <simgear/sg_inlines.h>
@@ -906,7 +907,7 @@ void FGAutopilot::set_AltitudeMode( fgAutoAltitudeMode mode ) {
              * SG_FEET_TO_METER ) {
 	}
 
-	if ( fgGetString("/sim/startup/units") == "feet" ) {
+	if ( !strcmp("/sim/startup/units", "feet") ) {
 	    MakeTargetAltitudeStr( TargetAltitude * SG_METER_TO_FEET );
 	} else {
 	    MakeTargetAltitudeStr( TargetAltitude * SG_METER_TO_FEET );
@@ -917,7 +918,7 @@ void FGAutopilot::set_AltitudeMode( fgAutoAltitudeMode mode ) {
     } else if ( altitude_mode == FG_ALTITUDE_TERRAIN ) {
 	TargetAGL = altitude_agl_node->getDoubleValue() * SG_FEET_TO_METER;
 
-	if ( fgGetString("/sim/startup/units") == "feet" ) {
+	if ( !strcmp("/sim/startup/units", "feet") ) {
 	    MakeTargetAltitudeStr( TargetAGL * SG_METER_TO_FEET );
 	} else {
 	    MakeTargetAltitudeStr( TargetAGL * SG_METER_TO_FEET );
@@ -932,7 +933,7 @@ void FGAutopilot::set_AltitudeMode( fgAutoAltitudeMode mode ) {
 void FGAutopilot::AltitudeSet( double new_altitude ) {
     double target_alt = new_altitude;
 
-    if ( fgGetString("/sim/startup/units") == "feet" ) {
+    if ( !strcmp("/sim/startup/units", "feet") ) {
 	target_alt = new_altitude * SG_FEET_TO_METER;
     }
 
@@ -943,7 +944,7 @@ void FGAutopilot::AltitudeSet( double new_altitude ) {
     TargetAltitude = target_alt;
     altitude_mode = FG_ALTITUDE_LOCK;
 
-    if ( fgGetString("/sim/startup/units") == "feet" ) {
+    if ( !strcmp("/sim/startup/units", "feet") ) {
 	target_alt *= SG_METER_TO_FEET;
     }
     // ApAltitudeDialogInput->setValue((float)target_alt);
@@ -957,7 +958,7 @@ void FGAutopilot::AltitudeAdjust( double inc )
 {
     double target_alt, target_agl;
 
-    if ( fgGetString("/sim/startup/units") == "feet" ) {
+    if ( !strcmp("/sim/startup/units", "feet") ) {
 	target_alt = TargetAltitude * SG_METER_TO_FEET;
 	target_agl = TargetAGL * SG_METER_TO_FEET;
     } else {
@@ -977,7 +978,7 @@ void FGAutopilot::AltitudeAdjust( double inc )
 	target_agl = ( int ) ( target_agl / inc ) * inc + inc;
     }
 
-    if ( fgGetString("/sim/startup/units") == "feet" ) {
+    if ( !strcmp("/sim/startup/units", "feet") ) {
 	target_alt *= SG_FEET_TO_METER;
 	target_agl *= SG_FEET_TO_METER;
     }
@@ -985,9 +986,9 @@ void FGAutopilot::AltitudeAdjust( double inc )
     TargetAltitude = target_alt;
     TargetAGL = target_agl;
 	
-    if ( fgGetString("/sim/startup/units") == "feet" )
+    if ( !strcmp("/sim/startup/units", "feet") )
 	target_alt *= SG_METER_TO_FEET;
-    if ( fgGetString("/sim/startup/units") == "feet" )
+    if ( !strcmp("/sim/startup/units", "feet") )
 	target_agl *= SG_METER_TO_FEET;
 
     if ( altitude_mode == FG_ALTITUDE_LOCK ) {
diff --git a/src/Cockpit/cockpit.cxx b/src/Cockpit/cockpit.cxx
index afbdb3140..32d8c3743 100644
--- a/src/Cockpit/cockpit.cxx
+++ b/src/Cockpit/cockpit.cxx
@@ -183,7 +183,7 @@ float get_altitude( void )
 
     float altitude;
 
-    if ( string(startup_units_node->getStringValue()) == "feet" ) {
+    if ( !strcmp(startup_units_node->getStringValue(), "feet") ) {
         altitude = current_aircraft.fdm_state->get_Altitude();
     } else {
         altitude = (current_aircraft.fdm_state->get_Altitude()
@@ -197,7 +197,7 @@ float get_agl( void )
 {
     float agl;
 
-    if ( fgGetString("/sim/startup/units") == "feet" ) {
+    if ( !strcmp("/sim/startup/units", "feet") ) {
         agl = (current_aircraft.fdm_state->get_Altitude()
                - scenery.get_cur_elev() * SG_METER_TO_FEET);
     } else {
@@ -247,7 +247,7 @@ float get_vfc_tris_culled   ( void )
 float get_climb_rate( void )
 {
     float climb_rate;
-    if ( fgGetString("/sim/startup/units") == "feet" ) {
+    if ( !strcmp("/sim/startup/units", "feet") ) {
         climb_rate = current_aircraft.fdm_state->get_Climb_Rate() * 60.0;
     } else {
         climb_rate = current_aircraft.fdm_state->get_Climb_Rate() * SG_FEET_TO_METER * 60.0;
diff --git a/src/Cockpit/hud.cxx b/src/Cockpit/hud.cxx
index 098e755c7..d362408db 100644
--- a/src/Cockpit/hud.cxx
+++ b/src/Cockpit/hud.cxx
@@ -38,7 +38,8 @@
 
 #include <GL/glut.h>
 #include <stdlib.h>
-#include <stdio.h>	//char related functions
+#include <stdio.h>		// char related functions
+#include <string.h>		// strcmp()
 #include STL_STRING
 #include STL_FSTREAM
 
@@ -648,7 +649,7 @@ int readInstrument(const SGPropertyNode * node)
 
     instr_item *HIptr;
     
-    if ( fgGetString("/sim/startup/units") == "feet" ) {
+    if ( !strcmp("/sim/startup/units", "feet") ) {
         strcpy(units, " ft");
     } else {
         strcpy(units, " m");
diff --git a/src/FDM/LaRCsim.cxx b/src/FDM/LaRCsim.cxx
index e24ca735d..e33b3485e 100644
--- a/src/FDM/LaRCsim.cxx
+++ b/src/FDM/LaRCsim.cxx
@@ -20,6 +20,7 @@
 //
 // $Id$
 
+#include <string.h>		// strcmp()
 
 #include <simgear/constants.h>
 #include <simgear/debug/logstream.hxx>
@@ -48,7 +49,7 @@ FGLaRCsim::FGLaRCsim( double dt ) {
     ls_toplevel_init( 0.0, (char *)(aero->getStringValue()) );
 
     lsic=new LaRCsimIC; //this needs to be brought up after LaRCsim is
-    if ( string(aero->getStringValue()) == "c172" ) {
+    if ( !strcmp(aero->getStringValue(), "c172") ) {
         copy_to_LaRCsim(); // initialize all of LaRCsim's vars
 
         //this should go away someday -- formerly done in fg_init.cxx
@@ -85,7 +86,7 @@ void FGLaRCsim::init() {
 // Run an iteration of the EOM (equations of motion)
 void FGLaRCsim::update( int multiloop ) {
 
-    if ( string(aero->getStringValue()) == "c172" ) {
+    if ( !strcmp(aero->getStringValue(), "c172") ) {
 	// set control inputs
 	// cout << "V_calibrated_kts = " << V_calibrated_kts << '\n';
 	eng.set_IAS( V_calibrated_kts );
@@ -169,7 +170,7 @@ void FGLaRCsim::update( int multiloop ) {
         speed_up->getIntValue();
     Flap_handle = 30.0 * globals->get_controls()->get_flaps();
 
-    if ( string(aero->getStringValue()) == "c172" ) {
+    if ( !strcmp(aero->getStringValue(), "c172") ) {
         Use_External_Engine = 1;
     } else {
 	Use_External_Engine = 0;
@@ -539,7 +540,7 @@ bool FGLaRCsim::copy_from_LaRCsim() {
     _set_Climb_Rate( -1 * V_down );
     // cout << "climb rate = " << -V_down * 60 << endl;
 
-    if ( string(aero->getStringValue()) == "uiuc" ) {
+    if ( !strcmp(aero->getStringValue(), "uiuc") ) {
 	if (pilot_elev_no) {
 	    globals->get_controls()->set_elevator(Long_control);
 	    globals->get_controls()->set_elevator_trim(Long_trim);
diff --git a/src/GUI/gui.cxx b/src/GUI/gui.cxx
index 67662bcc9..4c8e4b7cc 100644
--- a/src/GUI/gui.cxx
+++ b/src/GUI/gui.cxx
@@ -1060,7 +1060,7 @@ void guiInit()
     // Set up menu bar toggle
     gui_menu_on = ~0;
 
-    if (fgGetString("/sim/flight-model") == "ada") {
+    if (!strcmp("/sim/flight-model", "ada")) {
         guiToggleMenu(); // Menu off by default
     }
 }
diff --git a/src/Main/fg_commands.cxx b/src/Main/fg_commands.cxx
index 9dac586d5..820ae6156 100644
--- a/src/Main/fg_commands.cxx
+++ b/src/Main/fg_commands.cxx
@@ -1,5 +1,7 @@
 // fg_commands.cxx - internal FGFS commands.
 
+#include <string.h>		// strcmp()
+
 #include <simgear/compiler.h>
 #include <simgear/misc/exception.hxx>
 
@@ -244,7 +246,7 @@ do_view_cycle (const SGPropertyNode * arg, SGCommandState ** state)
 {
   globals->get_current_view()->setHeadingOffset_deg(0.0);
   globals->get_viewmgr()->next_view();
-  if ( fgGetString("/sim/flight-model") == "ada" ) {
+  if ( !strcmp("/sim/flight-model", "ada") ) {
       globals->get_props()->setBoolValue( "/sim/hud/visibility", true );
       if ( globals->get_viewmgr()->get_current() == 1 ) {
           globals->get_props()->setBoolValue( "/sim/hud/visibility", false );
diff --git a/src/Main/fg_init.cxx b/src/Main/fg_init.cxx
index 48f4af1f2..fcaf244f7 100644
--- a/src/Main/fg_init.cxx
+++ b/src/Main/fg_init.cxx
@@ -39,6 +39,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>		// strcmp()
 
 
 #if defined( unix ) || defined( __CYGWIN__ )
@@ -791,7 +792,7 @@ bool fgInitSubsystems( void ) {
 
     FGLocalWeatherDatabase::DatabaseWorkingType working_type;
 
-    if (fgGetString("/environment/weather/working-type") == "internet")
+    if (!strcmp("/environment/weather/working-type", "internet"))
     {
       working_type = FGLocalWeatherDatabase::use_internet;
     } else {
diff --git a/src/Main/main.cxx b/src/Main/main.cxx
index 4892ac57a..a19513348 100644
--- a/src/Main/main.cxx
+++ b/src/Main/main.cxx
@@ -48,7 +48,7 @@
 #include <GL/gl.h>
 
 #include <stdio.h>
-#include <string.h>
+#include <string.h>		// for strcmp()
 #include <string>
 
 #ifdef HAVE_STDLIB_H
@@ -310,11 +310,11 @@ void fgInitVisuals( void ) {
 
     // glFogi (GL_FOG_MODE, GL_LINEAR);
     glFogi (GL_FOG_MODE, GL_EXP2);
-    if ( (fgGetString("/sim/rendering/fog") == "disabled") || 
+    if ( (!strcmp("/sim/rendering/fog", "disabled")) || 
 	 (!fgGetBool("/sim/rendering/shading"))) {
 	// if fastest fog requested, or if flat shading force fastest
 	glHint ( GL_FOG_HINT, GL_FASTEST );
-    } else if ( fgGetString("/sim/rendering/fog") == "nicest" ) {
+    } else if ( !strcmp("/sim/rendering/fog", "nicest") ) {
 	glHint ( GL_FOG_HINT, GL_NICEST );
     }
     if ( fgGetBool("/sim/rendering/wireframe") ) {
@@ -820,7 +820,7 @@ void fgUpdateTimeDepCalcs() {
 	FGSteam::update( multi_loop * fgGetInt("/sim/speed-up") );
     }
 
-    if ( fgGetString("/sim/view-mode") == "pilot" ) {
+    if ( !strcmp("/sim/view-mode", "pilot") ) {
 	cur_view_fdm = *cur_fdm_state;
 	// do nothing
     }
@@ -1770,7 +1770,7 @@ void fgUpdateDCS (void) {
     
     // Deck should be the first object in objects.txt in case of fdm=ada
 
-    if (fgGetString("/sim/flight-model") == "ada") {
+    if (!strcmp("/sim/flight-model", "ada")) {
 		if ((fdm->get_iaux(1))==1)
 		{
 			obj_lat[1] = fdm->get_daux(1)*SGD_DEGREES_TO_RADIANS;
diff --git a/src/Main/options.cxx b/src/Main/options.cxx
index 4d72d4101..a190847ea 100644
--- a/src/Main/options.cxx
+++ b/src/Main/options.cxx
@@ -28,10 +28,10 @@
 #include <simgear/compiler.h>
 #include <simgear/misc/exception.hxx>
 
-#include <math.h>            // rint()
+#include <math.h>		// rint()
 #include <stdio.h>
-#include <stdlib.h>          // atof(), atoi()
-#include <string.h>
+#include <stdlib.h>		// atof(), atoi()
+#include <string.h>		// strcmp()
 
 #include STL_STRING
 
@@ -482,7 +482,7 @@ parse_wp( const string& arg ) {
 	alt_str = arg.substr( pos + 1 );
 	// cout << "id str = " << id << "  alt str = " << alt_str << endl;
 	alt = atof( alt_str.c_str() );
-	if ( fgGetString("/sim/startup/units") == "feet" ) {
+	if ( !strcmp("/sim/startup/units", "feet") ) {
 	    alt *= SG_FEET_TO_METER;
 	}
     } else {
@@ -610,49 +610,49 @@ parse_option (const string& arg)
 	fgSetString("/sim/startup/airport-id", "");
     } else if ( arg.find( "--altitude=" ) == 0 ) {
 	fgSetBool("/sim/startup/onground", false);
-	if ( fgGetString("/sim/startup/units") == "feet" )
+	if ( !strcmp("/sim/startup/units", "feet") )
 	    fgSetDouble("/position/altitude-ft", atof(arg.substr(11)));
 	else
 	    fgSetDouble("/position/altitude-ft",
 			atof(arg.substr(11)) * SG_METER_TO_FEET);
     } else if ( arg.find( "--uBody=" ) == 0 ) {
         fgSetString("/sim/startup/speed-set", "UVW");
-	if ( fgGetString("/sim/startup/units") == "feet" )
+	if ( !strcmp("/sim/startup/units", "feet") )
 	  fgSetDouble("/velocities/uBody-fps", atof(arg.substr(8)));
 	else
 	  fgSetDouble("/velocities/uBody-fps",
 			       atof(arg.substr(8)) * SG_METER_TO_FEET);
     } else if ( arg.find( "--vBody=" ) == 0 ) {
         fgSetString("/sim/startup/speed-set", "UVW");
-	if ( fgGetString("/sim/startup/units") == "feet" )
+	if ( !strcmp("/sim/startup/units", "feet") )
 	  fgSetDouble("/velocities/vBody-fps", atof(arg.substr(8)));
 	else
 	  fgSetDouble("/velocities/vBody-fps",
 			       atof(arg.substr(8)) * SG_METER_TO_FEET);
     } else if ( arg.find( "--wBody=" ) == 0 ) {
         fgSetString("/sim/startup/speed-set", "UVW");
-	if ( fgGetString("/sim/startup/units") == "feet" )
+	if ( !strcmp("/sim/startup/units", "feet") )
 	  fgSetDouble("/velocities/wBody-fps", atof(arg.substr(8)));
 	else
 	  fgSetDouble("/velocities/wBody-fps",
 			       atof(arg.substr(8)) * SG_METER_TO_FEET);
     } else if ( arg.find( "--vNorth=" ) == 0 ) {
         fgSetString("/sim/startup/speed-set", "NED");
-	if ( fgGetString("/sim/startup/units") == "feet" )
+	if ( !strcmp("/sim/startup/units", "feet") )
 	  fgSetDouble("/velocities/speed-north-fps", atof(arg.substr(9)));
 	else
 	  fgSetDouble("/velocities/speed-north-fps",
 			       atof(arg.substr(9)) * SG_METER_TO_FEET);
     } else if ( arg.find( "--vEast=" ) == 0 ) {
         fgSetString("/sim/startup/speed-set", "NED");
-	if ( fgGetString("/sim/startup/units") == "feet" )
+	if ( !strcmp("/sim/startup/units", "feet") )
 	  fgSetDouble("/velocities/speed-east-fps", atof(arg.substr(8)));
 	else
 	  fgSetDouble("/velocities/speed-east-fps",
 		      atof(arg.substr(8)) * SG_METER_TO_FEET);
     } else if ( arg.find( "--vDown=" ) == 0 ) {
         fgSetString("/sim/startup/speed-set", "NED");
-	if ( fgGetString("/sim/startup/units") == "feet" )
+	if ( !strcmp("/sim/startup/units", "feet") )
 	  fgSetDouble("/velocities/speed-down-fps", atof(arg.substr(8)));
 	else
 	  fgSetDouble("/velocities/speed-down-fps",
@@ -708,7 +708,7 @@ parse_option (const string& arg)
         fgSetBool("/environment/clouds/status", true);
     } else if ( arg.find( "--clouds-asl=" ) == 0 ) {
 				// FIXME: check units
-        if ( fgGetString("/sim/startup/units") == "feet" )
+        if ( !strcmp("/sim/startup/units", "feet") )
 	  fgSetDouble("/environment/clouds/altitude-ft",
 				atof(arg.substr(13)));
 	else
diff --git a/src/Main/viewmgr.cxx b/src/Main/viewmgr.cxx
index 27410d4c4..7cac8b84c 100644
--- a/src/Main/viewmgr.cxx
+++ b/src/Main/viewmgr.cxx
@@ -21,6 +21,8 @@
 //
 // $Id$
 
+#include <string.h>		// strcmp
+
 #include <plib/sg.h>
 
 #include <GUI/sgVec3Slider.hxx>	// FIXME: this should NOT be needed
@@ -130,7 +132,7 @@ FGViewMgr::update (int dt)
 	fgGetDouble("/orientation/roll-deg"),
 	fgGetDouble("/orientation/pitch-deg"),
 	fgGetDouble("/orientation/heading-deg"));
-  if (fgGetString("/sim/flight-model") == "ada") {
+  if (!strcmp("/sim/flight-model", "ada")) {
     //+ve x is aft, +ve z is up (see viewer.hxx)
     pilot_view->setPositionOffsets( -5.0, 0.0, 1.0 );
   }