Wizmouse may be just about the best little freeware app out there for those of us with Windows machines.
It’s pretty simple and straight forward. WizMouse allows you to scroll through out of focus windows using your mouse’s scroll wheel.
See, if you don’t ask your software to do much, and it does it, you’re a happy user.
Some immediate applications that come to mind are (besides general scrolling of out of focus windows) GMing from a laptop. Toggle between windows, scrolling up and down in the window behind your stats page, or current map.
However you use it, it’s a fantastic little thingy that does exactly what it says it will do.