Bing Desktop automatically changes your desktop background daily with the current Bing.com homepage image and provides you a Bing search box desktop widget or a taskbar search bar. Bing Desktop version 1.2 allows you to see your Facebook content right from the Bing Desktop.
"Bing Desktop delivers the beauty of the Bing homepage to your Windows desktop each day. Plus, get easy access to Bing search results via the desktop search bar or from the Windows taskbar without having to first open a browser. You can even access Facebook and trending news content right from the Bing Desktop."