1) Is based on real science - about 80% on average. (See this Popular Mechanic's article)
2) Cal Lightman and Gillian _____ (forgot her name) are based on two real scientists and their work (Dr. Paul Ekman and his partner).
3) There really are "naturals" (like Ria Torres), and they're VERY rare. Out of the 15,000 people Dr. Ekman studied, only 50 ended up being able to spot lies and micro expressions correctly more than 50% of the time. He calls them "Wizards at deception detecting".
4) One of the 50 people has a blog called Eyes for Lies and does consulting like Lightman's character. It's very interesting.
5) Dr. Eckman is actually consulted about every episode of Lie to Me, and writes a blog about the true science of each episode (which means that now I have to go back and start over with Season 1, and then go read about each episode after I watch it *grin*).
so cool.... I should probably go do something useful now.....