I wish I got paid for mentioning plentyoffish.com ... it's a great *completely free* site that's taking over the world. It's the biggest site for anywhere that's not American, but I think they're the 3rd biggest or 5th biggest in the states, so it's still quite populated.

I've met quite a few cool people from there, and one not so cool, but the good definitely outweighs the bad.