Any way to transfer clipboard between machines on the network?

ditto has a clipboard synchronization mode, although I have never tried how well that works. It's windows only and can only transfer images and text, but I use it even on a single PC due to its clipboard history.

I hear Synergy lets you do that. From what I read it works on Mac, Windows, and Unix. The only problem with this solution is that each computer would need it's own monitor, but it would let you get rid of the kvm.

You could also just use the kvm to switch monitors and not plug in the keyboard/mouse.

Synergy+ shares your clipboard - it allows you to copy text from one screen, then move your mouse to another screen, and and simply paste. Your clipboard is shared between all your computers over the network.