[vincesanity82]

One exhibit at the recent Performance Racing Industry show in Orlando, Florida (Competition, Dec. 17), drew more than its share of attention. And unlike the vast majority of exhibits, it featured software, not hardware. A company called iRacing develops stunningly realistic electronic re-creations of racetracks. The company was founded by Dave Kaemmer and John Henry. Kaemmer, an amateur racer, is co-founder of Papyrus Design Group, which developed the NASCAR Racing: 2003 Season and Grand Prix Legends games. Henry is principal owner of the Boston Red Sox, a major investor in Roush Fenway Racing NASCAR teams and a dedicated online racer. There are plenty of racing simulations available, but iRacing differs in the startling detail that goes into its racetracks, mapped out by lasers at an expense of some $100,000 per track to get more than 280 million points of reference, placed by more than 5000 photos per track. This is not so much a computer game as it is a professional flight simulator for race-car drivers. The idea is that it lets them show up at an unfamiliar track having already experienced it to a degree other simulators can't match. -- Auto Week

Closer to reality - AutoWeek Magazine

[DOF_power]

They (simulators) are allready used in F1.
The McLaren in particular is the best in the world.

Here's a look at the Williams simulator:
YouTube - F1 Williams Simulator