Google joins the privacy fray, offers up extension that blacklists tracking cookies
The extension, which is simply a free download from the Chrome Web Store, takes an utterly brute-force approach to the problem. It has a blacklist of known targeted advertisers, and it simply blocks any cookies originating from their domains. The blacklist will be regularly updated as advertising companies adopt the industry's self-regulated privacy standards.
Google notes that the extension is only targeted at U.S.-based ad companies, but a blacklist with European and international advertisers is in the works. The extension will also soon be updated to provide granular control over which cookies are kiboshed, so you'll be able to pick and choose which sites get to show you targeted advertising.