What's the best way to control two Macs from one laptop? I have an MBP and a MacPro. I tend to use the laptop a lot of the time but have need to control the workstation (e.g. for iTunes, DVD Player, TV tuning etc.) from another room or when I'm working at the MBP in front of the Pro.

Currently I use Screen Sharing to do this, but it is perhaps not the optimal solution when dealing with multiple monitors (3 on the Pro). Ideally I'd like to be able to move the pointer off the screen of the MBP and have it appear on the monitors as if the laptop were connected directly to them. 

I think I saw an open source solution about six years ago but I can no longer locate it. Does anyone have any leads ...?
It may not work ideally for every use case (you'd need to be near the monitors), but I can highly recommend QSynergy which will allow you to use one machine's keyboard and mouse to control the other.