Windows only: Tiny application DesktopOK saves and restores your desktop icon positions—so your perfect icon layout won't get lost if your resolution changes when hooking to another monitor or playing a game.
Using the application is easy enough—just use the save and restore buttons, which work exactly as you would expect them to—the nice feature about this application is that you can save multiple layouts, which could come in handy if you regularly switch between an external monitor and the laptop screen. The application doesn't need to be running all the time—you can simply save your layout and then only open it again when you want to restore the layout.
If this utility just isn't for you, you can check out previously mentioned Shock Desktop to save your icon layout, or take a look at Fences, a seriously awesome way to organise your desktop icons. If you want a solution that works from the Explorer context menu, check out an icon-layout-saving Explorer plug-in that I've previously written about.
DesktopOK is a free download for Windows only—it didn't work under Windows 7 in our testing, but should function correctly in Windows XP—if you get it to work in Vista or Windows 7 let us know in the comments. Thanks, Shankar!