The other annoying thing about switching between laptop keyboards is how variable the key layout is (I'm quite partial to my thinkpad, but the ctrl isn't in the same place as others and once you get used to it, you find that you confuse emacs quite regularly on other keyboards). The solution to this problem? Synergy2, which lets you use one keyboard and mouse with multiple computers/screens.

(Note I've only used it with linux thus far, but is has support for windows and mac as well)
... I've been using synergy for the past year or two (on mac and windows)
It just works great!
Yeah, synergy is really great. I use it on Windows -> Mac. On the Mac
side, you really need to get QuickSynergy which allows you to control it in
the menu bar. Synergy makes PC gaming wonderful. I can play on one
screen, and surf / IM on another. I'd like to see his "future TODO"
feature list expanded (especially the N computers bit, now it just works on
1-3 horizontally). But who needs 4+ computers?
Synergy2 seems to have a very limited audience. Most people are only going
to use one laptop at a time and the transition from laptop to desktop
doesn't seem to have held most people back.