Queue evil laughter...
QuickSynergy is a graphical interface (GUI) for easily configuring Synergy2, an application that allows the user to share his mouse and keyboard between two or more computers.
QuickSynergy seemed to be the most stable of the Synergy2-based (http://synergy2.sourceforge.net/) UIs for Mac. Synergy allows you to share one keyboard and mouse with multiple computers. Imagine dropping your laptop down next to your desktop computer and sharing a keyboard and mouse between them simply by dragging your mouse to the edge of your screen and having the mouse appear on the laptop and vice versa. It also supports a shared clipboard (text only). It does not support synchronized screen savers and single login unlock. Although this is probably for the better for security reasons.
And speaking of security, I would only recommend running this software within trusted networks. This was a little too easy to setup and I suspect it is easily hackable. I would not recommend running this all the time over an untrusted wi-fi network.
I tried SynergyKM (http://sourceforge.net/projects/synergykm/) but it did not work for me. Teleport (http://abyssoft.com/software/teleport/) is another option, but is Mac only. Synergy is truly multi-platform supporting Linux and Windows in addition to Mac. This would allow you to drop down your Mac laptop next to your Windows desktop and do the same kind of keyboard sharing.
