Sharing keyboard/mouse via software with another computer? I have my workstation with Windows and a MacBook with Mac OS X which I attach to the same monitor. The monitor provides the switching but I don't want to have two keyboards and two mouses and neither use an external switch (already enough cables).

Is there a solution. The keyboard needs to stay attached to the windows desktop, so it must be a network software solution on the Apple side.
I'm not sure if it will fit this specific use case but if you can forego the shared monitor, you can use a tool like Synergy or Share Mouse. 

FWIW, I've used Synergy before across 3 computers and it worked well.