Hot on the heels of Mozilla's proposed Do Not Track solution, Google has
launched Keep My Opt-Outs, an extension for users who aren’t comfortable with personalization of the ads they see on the web. It’s a one-step, persistent opt-out of personalized advertising and related data tracking performed by companies adopting the industry privacy standards for online advertising.
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.
For now, only targeted at U.S.-based ad companies
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.