He's got your personal data, relationship status and those pictures from last night -- now Mr. Zuckerberg is aiming for a share of your desktop, too. Facebook has released a desktop messenger client for Windows 7 that brings you access to the site's chat, ticker feed and notifications without everyone in the office spotting the blue-bar-of-lost-productivity across the top of your browser. It's currently in limited beta, so there's still time to build a rival client -- maybe with some support from the Winklevii?