You might want to look at a Synergy client on OS4. It looks like there is one on OS4Depot here:
http://os4depot.net/index.php?function=showfile&file=network/misc/amisynergyc.lhaSynergy, in essence, is a software version of a KVM. It lets you share the keyboard and mouse between multiple machines. You'd still have to swap inputs on your monitor or set up multiple monitors, for which it has additional support.
