I did it and found it to be very interesting, I'm a carrier for Gaucher's. It also gave me some things that I have risk factors for as well as interesting information about my genetic background. A friend found out that he was a carrier for cystic fibrosis and that helped explained why he and his wife were having trouble conceiving. Another friend did it to find out my information about herself since she was adopted. However, now because of the FDA, 23 and me can only offer ancestry information.

A friend of mine and his sister used it and he found out the man who he thought was his biological father really wasn't.

Is it reliable?
How does it work? The website is a bit ambiguous.
Did you feel that it was accurate?