Ctrl + Arrow keys: Leopard's virtual desktop (in spaces) is a keyboard shortcut that is really easy to move through. But that's not the only way.
Warp is a preference panel to use the mouse to move in space. Moving from one screen to another and adjacent to one side or the other moving your mouse as easy as waiting for a place to meet.
You can set the application to access the screen before you place adjacent to the edge of the mouse, how much time was left. You can also enable / disable the keyboard option and you are about to access, can show a thumbnail of the other choices indicated.
|Free||1.2.3 for Mac||Kent Sutherland|