I've looked at AFF before, but I didn't really find anything or anybody there that was to my liking. This was when I was between relationships (after a break-up) many years ago.
Always, always use a freebie e-mail that you don't give a damn about for this stuff. The box will get filled up with spam. Don't use your real e-mail.
These set-ups aren't exactly a scam, but there is a shadiness involved due to the very nature of the site and the reasons that people are there in the first place. There's a fine line between casual sex and prostitution.
I've had better luck finding people on regular socializing sites as opposed to dating or sex sites. With socializing sites, even if nothing happens in terms of dating or sex, you can still make some pretty cool friends.
Dedicated dating-specific sites like Match.com really suck in my experience. I've never managed to meet anybody off of those. I've probably used them all at one time or another.
I've actually had a lot of luck in the past with studentcenter. MySpace can work, too. Facebook is a possibility as well; you might start talking to someone who you notice is on your friend's buddy list, for example.