Warp

To move through Leopard's virtual desktops (the famous Spaces) there's a keyboard shortcut that's really simple: CTRL + the arrow keys. But that's not the only way.

Warp is a preferences panel that lets you use the mouse to move between Spaces. Moving from one to the other is as easy as moving your mouse to one edge of the screen or the other and waiting for the adjacent space to show up.

The application lets you set how much time you have to leave the mouse at the edge of the screen before you access the adjacent space. You can also activate/deactivate the keyboard option and show a thumbnail of the space you're about to access, among other options.