I'm going to be selling my hackintosh soon and buying a 20 inch iMac. But i'll be keeping my current 20 inch screen and using it with the mac. I know I need the cord, but as far as software goes I don't know what I should get for having a dual screen setup. Any cool apps/widgets or whatever for dual screens? Also is there any way to overcome the problem with having different screen calibrated differently(and thus badly on atleast one).