WizMouse is a simple but ingenious tool that allows you to use your mouse scroll wheel on the window under the mouse cursor - not the one that currently has the focus.
This is a small step, but a useful one. Just think how many times you've spun the mouse scroll wheel only to find it doesn't affect the application you're looking at, so you have to click that program window and try again. With WizMouse it's much more natural: if your mouse cursor is over a particular window, then that's the one that will be scrolled by the mouse wheel.
As a bonus, WizMouse can also allow you to use the mouse wheel in applications that don't normally support it, translating mouse wheel movements into scroll bar commands that work everywhere.
The program worked faultlessly for us, but if you do run into problems with some applications then you can toggle WizMouse on and off by simply clicking its system tray icon.
And while it has to run in the background to do its work, WizMouse doesn't use too many resources, consuming just a little over 3MB of RAM (private working set) on our test PC.