Both computers have the same size display I think. I know the 12in iBook uses a mini VGA adapter, but the Lime iBook does not have VGA out, it only has composite video out. I know there is a switch that lets you control 2 computers by using only one monitor, I think Belkin makes its, although it does not support composite video so unless you hook up your Lime iBook to a TV the monitor cannot be expanded.