I saw a piece on Planet Ubuntu about an app that lets you use one keyboard and mouse on two computers on the same network. QuickSynergy. It is a breeze to set up and works like a charm.
Many times I'm sitting at my desk running both my desktop box and my laptop. When I'm working on the UWN, it's a must almost for me. Having to change from my desktop keyboard and mouse to the laptops involves leaning forward, and that causes back and shoulder pain after about 30 mins. or so. With QuickSynergy, this is eliminated.