Just downloaded a little utility, sure it was an early April Fool's joke . . . but it's working, and I'm stunned! I work on two Macs (a PowerBook and an iMac) with one keyboard/mouse ergonomically arranged, using a primitive USB switch to jump from one to the other - wires everywhere underneath, ho-hum!
The freeware program Teleport claims to let you use one mouse and keyboard to control several Macs. "Right!", I thought. "Pull the other one!" . . . But it works like a dream (even though it's only a public preview at this stage)! Install the little prefpane on the Macs, choose one as the 'Master' and arrange the screens (in a drag and drop way) as you wish. Mine are side by side in reality and in the prefpane, so my cursor just slides from edge of PowerBook into the iMac screen (with little warning left on PowerBook screen, as seen in the screenshot at left). Wow!
It'll confuse me when I take my (AirPorted) PowerBook downstairs to work, but ... wow!
[robg adds: This really is a pretty amazing little program; I tested it with my PowerBook sitting next to my G5, and it works exactly as described. The only problem I had was when I wanted to capture the screenshot of the controlling icon you see above. I used Grab and a 10-second delay, and after Grab took the shot, the mouse control had moved back to the main machine, and I couldn't get back to the PowerBook -- deactivating and reactivating Teleport, though, fixed the problem.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20040210120805511