I bought this KVM: http://catalog.belkin.com/IWCatProductPage.process?Product_Id=357928
Then I realized that it is intended for digital-only DVI (DVI-D), my VGA to DVI adaptors (DVI-I) do not fit because they have four extra prongs for the analog signal.
And another issue. I tried to use it only for switching the keyboard and mouse, and for some reason the remote control button that does the switching doesn’t work. Does the monitor have to be plugged in as well to work properly?