Has anybody used Intrade??

I came across this site last night and found it very interesting www.intrade.com It appears to be like the stock market except you buy/sell on events, like who's going to win American Idol, who's going to be the next pope and so on. Is there anybody out there that has used this and has had any experience with this website???

www.anybet.com is another one like that.

I cant speak for its legitimacy though...