try teleport mac, howevre both machines need to be running os x on the same network but you could network em with bluetooth anyway.

It works wonders for me as a software KVM between my iBook and my Quicksilver
Macbook Pro 15.4" 2.53GHZ Core 2 Duo 4GB RAM
Powermac G5 Dual-Core 2.3GHZ 2GB Ram
Powermac G4 Quicksilver 733MHZ 1.25GB Ram
iPod Video (1st Generation) 60GB