CPM ads are available on so many advertising networks, including Adsense and Adbrite.. However the pricing of these kind of ads are based on impressions / page views, the more your ads show the more you will get paid..
w0w GUYS, I think he is talking about the effective CPM on your adsense reports page. Well this goes back to the age old adage " get in a good niche " Also work on improving your ad placements on your page. Don't go with the 1/2 page above the fold ad block (Then people will instantly divert their eyes) but try to place your ads where people will be looking when they are done with the page or are wanting a little bit more on the topic.