MultiBox Client & Server: http://ultrashare.net/hosting/fl/ffeff6c466/
MultiBox Client & Server & Source: http://ultrashare.net/hosting/fl/7648e6e966

Features:
* One mouse/keyboard can control multiple computers without any additional hardware.
* Specifically designed to allow you to play 3D games that use the mouse for looking around.
* Ability to toggle "broadcasting" with a hotkey that will allow your keystrokes or mouse movements to be broadcast to all connected computers.
* Simple UI: Setting up monitor layout is very easy.
* Runs in the taskbar so it's out of the way.

Run MultiBoxServer.exe on the machine with the mouse/keyboard. Run MultiBoxClient.exe on every machine (including the one with the mouse/keyboard). Set the port on the server machine to something and match it on all the clients (including the one with the server software running on it). On the clients, enter the hostname of the server into the Server Name (this is the name of your computer if you are on a local area network) and press enter.

Note: Be sure to connect the client on the same machine as the server first, otherwise you won't be able to get back to that machine without quitting all the others first.

Pressing escape 8 times in a row will exit the server in case something breaks and you have lost control of the mouse/keyboard somehow.

There are a few things that need worked on but on a whole it should work pretty well. This version is fairly large because it's compiled in debug mode (release mode crashes for some reason) but I'm assuming anyone multi-boxing has a big enough internet connection to download a 10MB executable.

The source code requires wxWidgets 2.8.0 to compile and run as well as the Windows SDK. It currently only works on Windows XP (95/98 probably won't work and 2000/Vista are untested). It definitely won't work on a Mac or Linux but it is mostly written with portability in mind (wxWidgets API instead of .NET) so if someone is interested a port isn't terribly unrealistic.[/list]