Looking for ways to sell some traffic? Join http://www.trafficbroker.com and sign up as a Publisher. Once signed up wait for approval then you can add some domains and wait for them to be approved. Once approved go to Ad Codes and in there you can get the ad codes to ad to your site(s). Make sure to always pick the domain you want ads for from the pull down menu. In the other pull down menu you have different ad options - 320x250, 120x600, 140x600, 160x600, 728x90, 900x250, Floating IM, Popunder. Plenty of different options that will fit perfect for your site(s)
Check it out, test it out and see how it works for you.