I know this is nerd-mania, but you have to agree that the MacBook Air 11″ with the iPad as an extra display is a pretty royal setup! Check out the Air Display app from Avatron Software and try it out for yourself. Good to know is that it has a bit of lag because it’s using the UDP-protocol over WiFi, but it’s perfect for a text document or website you’re writing commentary on, Spotify or whatever else that is fairly stationary. Nerdy but extremely useful!
Oh, did I mention that you can use it for touch input too? Oh, geekgasm.