So sayeth lifehacker:
You don’t need a hardware switch to share one keyboard and mouse amongst several different computers. All you need is the free, cross-platform application, Synergy.
I wondered about that, so I decided to give it a shot. It works AMAZINGLY!
I have a few computers in my classroom, and am constantly getting up to go help a kid with a problem. Normal, right? Usually it’s a matter of telling them where to click or something minimal. I’m not fussing, but I am more effective when I can be centrally located on my machine helping them from a distance sometimes.
Here’s my new setup…
When I move my mouse to the extreme top of the screen, it takes control of the mouse and keyboard of the computer across the room. When I move the mouse extreme right it takes control of the computer on the right side of the room.
Amazing, right?
It’s not that I don’t want to go help, but this allows for quick fixes without my having to go over there so I can keep moving here helping others doing other things…
Lifehacker’s guide to setting this up makes it incredibly easy, totally free, and works with Macs, PC’s and the like. Not sure about linux, but it’s open source and I did see both binaries and source so I am certain you could compile it for yourself. There may be a linux version, I didn’t check, can’t run my Puppy here in school any more 
Either way, you HAVE to check this out!
Hack Attack: Control multiple computers with a single keyboard and mouse – Lifehacker
Update: Just read the article more carefully, if you’re running Linux, grab the platform independent version. Added some more links, too.
Oh, nice!
This is why I started reading your blog in the firstplace Christopher; for all of the really cool open source tools. We have commercial versions of software that does what you describe, but I’m not allowed to use it
I’m thinking that perhaps with this I could control the computers in my lab without bothering the Tech Director about trying to get me OKed to use the Novell stuff we have on our machines.
Hi Chris,
Cool tool! I thought you may also be interested in I have to wait until the summer to install it in our labs, but I’m looking forward to giving it a try. It sounds just like but it’s open source.
Let me try that again, my links got messed up. The tool is Teacher Control Panel on Source Forge. and it’s looks like Syncroneyes, but it is free. Worth a look..
As far as I know, Linux has been supported for a long time as well.