Using Google Ad Words? You should be. As SherpaBlog points out, their activity is starting to rival Overture, which I can personally attest to. Here is a guide on making the most of your Google Ad. How To Write Little Tiny AdWords Ads That Bring Giant-Sized Profits

BTW: Google has been putting my ad across the top of the page sometimes, apparently if there are no big dollar spenders for the targeted keyword. (The ads across the top are only for those with large spending with Google, like $5,000 a quarter.)