Up to recently, there was "just" a MacBook and a spiffy 24" wide screen on my office desk, with an Apple keyboard and a mouse to this since the large screen is the main one.

Alas the Venice Project (now Joost) client software doesn't yet run on Mac (but we're working hard on it) so I recently got an additional windows laptop to run it. And I found myself often wanting to move the mouse cursor from the main screen to PC on the right, just as I do on the left to go the MacBook's screen.

Of course, it didn't worked until I found this little gem: Synergy, a very simple program that allows sharing a keyboard and mouse over an arbitrary number of computers running MacOS, Linux or Windows. Edit a simple configuration file that describes the relative placement of your screens (right and left, but also top and bottom!), start the server on the computer owning the keyboard and mouse, a client on other computers, and the magic kicks in! The mouse travels smoothly from one computer to the other, and the keyboard follows it. And as an additional bonus, the clipboard is shared!

One keyboard and mouse for all computers: this rocks! Now I can consider adding a 4th one :-)

Only precaution: make sure the server accepts incoming TCP connections on port 24800.