Bluekai

If youre totally creeped out by behavioral advertising and would rather avoid it altogether, the best thing for you to do is go to this Network Advertising Initiative page, select all and opt out.

Youll still see ads on the Internet, but they wont be tailored for you (and its possible, according to BlueKai CEO Omar Tawakol, that as a result you will see more and more disruptive ads to make up the difference in lost revenue)

Source: http://gigaom.com/2010/08/03/exelate-raises-15m-for-targeting-ads-aka-the-wsjs-spying-on-users/