I have dated 2 guys I met online--mind you, I'm a youngin', so by "online" I mean facebook and myspace.

Mr. FB turned out to be a RUFF RUFF DOG.

We talked for a couple weeks after he "approached" me, then met because our schools were close to each other. We talked everyday for 2 months and were definitley "more than friends" when I found out about his fiancee (on Valentine's Day, by the way). Don't know if they're still together, one of my friends turned out to know one of the fiancee's friends and it all got back to her. I swore I'd never date a man off the net again, but Mr. MS caught me off guard.
Mr. MS was actually very decent. I used to work in a security office, so I ran a mini-background check on him. He was totally legit and everything he told me about himself checked out. Only then (after about a month), did I agree to meet him for a movie. We went for a walk around the plaza afterward, hit it off, and ended up dating for about 4 or 5 months (ALWAYS in public places). It didn't work out, but it was worth it; it was a good reminder that there are some good men out there; I'd almost forgotten. So
just be careful and don't do anything you aren't comfortable with. The net is fishy, but you might find a good catch.