Developer of high quality games Firemint, especially known with their best selling iPhone air simulation Flight Control, now released most waited race game, Firemint Real Racing at App Store for $10. I will straightly claim that it is currently the best iPhone race game you can find there. PSP fans who claim iPhone is not for games, should be really jealous seeing the wonderful 3D graphics, high quality audio of engine sounds, flawless multiplayer game mode and clever AI implementation.
Real Racing Game offers 36 cars, 12 tracks in three racing divisions. As a beginner quick race is a good start with default controls. You can change default settings to according to touch or tilt input. For example, auto or manual acceleration, brakes. After playing some time, you can change into career mode where you participate on several racing events (total 57) and reveal new types of cars (Sedan, Hatchback, Muscle :) according to your experience. By the way, it is not easy to complete all career mode, it can take several hours.
It is not the end of the game. You can even join a centralized online league to compete against other human racers. So, maybe it will take weeks until you become bored of it.
If you will spend money on a racing game, do not think twice. Highly recommended!