Yesterday, Microsoft released a new app for Windows 7 PCs called Bing Desktop (it was in beta for the last few weeks). It's an interesting move as Google as had their Desktop app for years (it's also a little creepy as it can search your hard disk).
Luckily, Bing Desktop does no such thing and darn it all, it's awesome to boot.
For one, it can download the Bing wallpaper daily to your PC and makes it your desktop background. Next, there's a nifty Bing Search bar that sits on your desktop and allows super quick access to Microsoft's increasingly awesome search service. Pro tip: pin it to the top of your screen and you can tap to bring it down anywhere for quick lookups-- Microsoft really nailed the interaction here in our opinion.