Synergy to the rescue! It's an app that allows you to share the mouse and keyboard from one computer to others, and it's cross-platform. I followed the instructions at GroovyPost: http://www.groovypost.com/howto/review/synergy-share-your-keyboard-mouse-with-multiple-mac-windows-or-linux-computers/
One gotcha -- I normally use Dvorak, and if both my windows and mac machines are set to dvorak, it doesn't work properly. I have to set my mac to use the normal keyboard layout to get proper input, but that's a small price to pay for the convenience.