Tilt Racer lets you use your phone as a steering wheel with nearly any game on your PC. You tilt the phone to steer, and use a slider on the screen to control the throttle and brakes. It even uses haptics to let you FEEL the controls.
Touch Pilot One allows you to control a flight simulator from your tablet. Use the on-screen controls to adjust your throttle, gear, flaps, and more with just a touch.