How To Shade Windows With Mouse Wheel

Scroll your mouse wheel in the up direction when your cursor is over the title-bar of a window. That window should now animate by sliding into the title-bar, therefore shading the window (assuming you're using CompizFusion). If this isn't the case, you can fix it by doing the following:

1. Press Alt+F2
2. Type gconf-editor
3. Expand the aps folder (in the left column tree)
4. Select the gwd folder
5. Double click the mouse_wheel_action key in the right column
6. Type shade into the value field
7. Press OK and close the configuration editor. 

Thanks to the following forum post for this solution: UbuntuForums