Here's an inventive game by Balazs Vagvolgyi where you drive a car around different tracks in 3D.  You can choose easy or hard, change the graphics and choose how many laps you'd like to do.  Balazs' instructions say:

Use the left and right arrows to steer the stunt car. Tap on the +/- buttons to accelerate and decelerate. The penalty for leaving the ramp is the time the crane spends with lifting the car back on track. Records get registered after the race is competed. Hall of Fame is saved in cookies on the web browser. Play on easy difficulty level to enable steering assistance. Dynamic background and z-blending are disabled in the low graphics mode for smoother gameplay. If you experience sluggish performance reset Safari by holding down the Home button for several seconds until the Home menu appears then restart the game.