If you have traffic that is male bi-sexual or bi curious, check out BiParty.com.
It's run by a friend of mine and I can vouch for his excellent conversion and rentention rates.
Of course, BiParty.com is a unique niche so you need to have the right kind of traffic.
Here is his sponsor site to sign up:
www.OriginalBucks.com
And I can't resist throwing in a little plug for me ... if you have female traffic, especially mainstream traffic, you might give bingo a try. Click on link in my sig.