I just picked up one of Apple's new aluminum keyboards which is incredibly slim and quite nice to type on, contrary to appearances.

The problem I've run into is that it lacks the vestigial "scroll lock" key that is generally on the right hand side of the function key row. Most KVM switches use a double-tap of the scroll lock key to invoke a switch of input. After much searching of Google, I ended up purchasing a new switchbox: the Belkin Flip Wireless. It's pretty nice since it features a small wireless "puck", that when depressed invokes the input switch. Now I can switch between my Mac and Thinkpad and I really like the tactile click when I switch between devices.