AdHearus

AdHearus (http://adhearus.com/webmaster.php)
AdHearus is a very feature-packed contextual ad provider. As with AdSense, advertisements are targeted but it doesn't stop here at all. The ads are very flexible, you can select from text-ads, banners, rectangles, pop-ups, pop-unders or skyscrapers. You can also display your own ads, through rotation, both on your site and on other affiliate sites, which makes AdHearus a hybrid with conventional advertising technologies. There's a very comprehensive on-line real time reporting feature and, as usual with such services, starting out is free and it's a breeze.