IOSPIRIT has released Spacious 1.0, which allows switching between Mac OS X 10.7 (“Lion”) Spaces and fullscreen apps with every mouse. It’s available for US$5.99 in the Mac App Store.
You can switch via the Spacious Navigator that’s shown when the mouse cursor is moved to the display borders. Or directly with many mice wheels.
The Spacious Navigator appears when you move your mouse to your display’s borders and keep moving. Click on the Navigator to switch to the next or previous space. You can right-click on the Spacious Navigator to access recently used applications and Mission Control.
Hover over an app’s icon and a close button appears, allowing you to quit that app. If your mouse wheel can scroll left and right (often possible by tilting it), you can turn on an option in Spacious and use it to switch to the next and previous space instead.