Dating on the internet - IMO I think the internets is great for holding a long distance relationship together. I met my S.O. in college. After we graduated they moved back home with their parents for a year and a half. But we still dated. Luckily they weren't too far, so we could actually meet up every couple of weeks. But in between that time we'd have "dates", where we'd turn on our webcams, each get a glass of wine, turn on the same channel on TV, and watch it "together".
Horray for webcams and e-mail. I can't imagine trying to do a long distance relationship with snail mail, and photos, instead of daily e-mails and webcams!
Meeting someone on the internets - This, I am not too sure about. I have a crazy coworker. She's 34, and she uses plentyoffish.com (or something like that). Every time she goes out on a date with a new guy, I feel so sorry for the guy! They have no idea that they are about to go out on a date with a really crazy person! However, I do have internet friends that I have talked to since high school. If I were single, I would have considered hooking up with them. But I'm pretty sure I wouldn't officially "date" them, until I had gotten to know them in person.
JMHO