Synergy: share a single mouse and keyboard between multiple machines

Synergy is an open source application that lets you share a single keyboard and mouse set among your multiple machines, even across operating systems (including Mac OS X, Windows, and most flavors of *NIX). Assuming each has its own display, you can redirect the keyboard and mouse simply by moving the mouse off the edge of the screen. But wait, there's more -- Synergy merges the clipboards of the various systems so you can cut and paste an item from your Mac over to your Windows box directly, without having to route your text via IM/email/file/other awkward method we've previously stitched together. It can even synchronize your screensavers so they all start and stop together. Open source. Free. Check it.

[Thanks, Eddy]