Three sites, $25 per signup:
http://www.oralcash.com/
$32 per signup:
http://www.frostedbucks.com/
The first one is run by some good friends of mine - I've known them for about 5 years now. The sites convert really well.
The second one, well, I'm going to say its iffy. The tour needs a lot of work but if you think you can work with it, it might be worth a shot.