Chrome: Currently Windows-only, Set Image As Wallpaper is a simple extension for Google Chrome that adds in the set-as-wallpaper right-click context menu functionality present in Internet Explorer, Firefox and Opera to Chrome.
If you're used to setting your wallpaper from images you find on the web, it's more than a minor inconvenience that Chrome doesn't have a simple right-click context menu for setting your desktop wallpaper. The Set Image As Wallpaper extension not only adds the right-click context menu back in, but it pulls up a basic adjustment menu where you can stretch, tile or centre the image — seen in the screenshot above.
Set Image as Wallpaper is currently a Windows-only extension, hopefully it will be ported to OS X and Linux edition of Chrome soon. For great wallpapers to try out the extension, hit up some of the sites in the Hive Five Best Wallpaper Sites.