The folks over at Forwarding Address: OS X today mentioned an app named teleport, an amazing-sounding preference pane that lets you move your mouse from the monitor of one Mac to another Mac just by moving past the edge of the screen. If you've ever used two Macs you'll know how cool this is! I no longer have two side-by-side Macs, but I'm looking forward to trying this out. Be warned, some of the comments at both the Forwarding Address page and the MacUpdate page mention bugs, but by and large the comments are extremely positive.