I know a bunch of people who customize the appearance of their desktop, but many don’t know that Windows 7 supports themes that rotate between desktop backgrounds and automatically adjusts the color of the Aero interface. The thing most users don’t know is that Microsoft actually has a site that offers Windows 7 themes. The themes are broken up into various categories including holidays/seasons, landscapes, automotive, and much more. In all there are about 180 available including a theme for Angry Birds.
If you’re running an older version of Windows that doesn’t support themes you can always jump on over to Microsoft’s desktop background page that includes over 200 high-quality backgrounds you can grab. Many of them are really amazing and are definitely worth browsing if you haven’t done so already.