Can't be done.. Here's what i did - I wanted to use my nice LCD monitor for Win and my new linux box... without traveling to 2 desks or remoting in. I found out that my monitor has mulitple inputs! yay - i have 2 boxes, 2 keyboards and mice, and 1 monitor. I can just tap a switch and change the inputs for whichever PC i'm running. Not the best solution, but i can deal with 2 KB/Mouse.
I did this because DVI KVM's are halla expensive. You can purchase cheap VGA/PS2 KVMS from ebay - i got an 8 port switch (with standard power cable, none of that AC/DC poop).