Although you might already be using this, nifty program i have been using for a while.
Its called 'Synergy' - Its basically keyboard and mouse sharing over a network (wireless or wired), its cross platform and very good.
Not intending to show off, but i have 3 seperate computers here with 3 seperate screens:
Vaio Laptop 16" Screen (yes yes its a Sony)
Mac Mini - Connect to a 19" TFT
Normal PC - 15" TFT
3 seperate PC's networked.
Synergy allows you to share you keyboard and mouse from one computer to others. So you only have to use 1 set, its basically like a KVM with out the V

I have it set on my MacMini in both windows and Mac, i have my 2 other screens next to my 19" and i can take my mouse to the edge of the screen on the MacMini, and it magigally appears on my laptop screen!

I go back can take it across 2 screens to my right hand side 15" which i use for iTunes!

Really is nifty and its like having 3 monitors connected to one PC, although you can't drag windows between them.
As i said its cross platform too, so when i am on my mac in Mac, i can take my mouse across the screen from mac and it appears on my windows laptop, I can type in there with the keyboard, and whats really cool is i can copy and paste text from 1 pc to the other! Very handy
Link:
http://synergy2.sourceforge.net/Its a bit fiddly to get working, but easy enough any problems PM me
