These are the forums that I have found that will pay you to post:

www.mylot.com

A wonderful community of posters from all over the globe. What I like about this site is your are rewarded for giving quality discussions.

www.dormcheck.com

This is a fun site,not as big as Mylot, but growing. There are a few other ways to make money on this site found under the Boosters option.

www.CraZoo.com

This is also a nice site. Currently pays users $0.03 per new thread, $0.02 per post and $0.002 per referral..you do have to get your account activated on this site before you can start posting.

While these forums are not going to make you rich, it is a fun way to fellowship with others, and a very nice perk that you get paid for your discussions.