Apple's How-to: share your keyboard, mouse, monitor and internet connection
Back when the Mac mini started shipping, everyone got a quick lesson in the joys of KVM switches. There are even ways to avoid using a KVM switch to share keyboard, monitor, and mouse between machines. Apple has posted their own how-to, and it's not just how to plug in the cables on a KVM switch... The article is part of a comprehensive look at how to migrate your old PC data to your shiny new Mac, and keep them co-existing nicely. A good sheet to print out for anyone who might be getting a shiny new Mac for the holidays, especially if they're planning on keeping their old busted Dell around for playing something other than WoW.