Do you have more than one computer on your desk? I think most of us have both a laptop and a desktop, perhaps more than one of each. In the old days, you would have had to buy a piece of hardware called a KVM to deal with this situation, and that sucked.
But now there’s Synergy Plus, a free software application for sharing a keyboard and mouse between two or more machines. It works over your existing network and even shares the clipboard (text only) between machines.
Best part? It works on all three major platforms: Windows, Mac, and Linux.
If you’ve never tried it, or if you have an older version, i.e. Synergy2, give Synergy Plus a try. It’s not too hard to setup — just make one computer the server, configure it, and set the others to be clients. There’s a full configuration guide here.