I've just purchased a Logitech Attack 3 usb joystick and it
works great with Flightgear.
It has 11 button and a throttle control.
I have attatched an xml file for inclusion into Flightgear.
The buttons are as follows:
Trigger Button 0 : Brakes
Button 3 : Elevator trim up
Button 2 : Elevator trim down
button 6 : Elevators up
button 7 : Elevators down
button 8 : Brake left
button 9: Brake right
With buttons 11 - Gear up
Button - 10 Gear down