Push the pre-order button?
If you are one of the few people who didn't wipe their memory of Star Wars: The Phantom Menace, you can now be like Anakin Skywalker with the aid of Portal 2. I don't mean become annoying and introduce the concept of Midi-chlorians that undermine everything in the Star Wars Universe ..., but build your own robot!
Pre-Orders from Gamestop will be rewarded with the ability to customize the dynamic duo of robots who feature in the co-op section of Portal 2. Having already enjoyed their antics in the extended trailer for the game, I'm not sure that you would want to change anything about their little chrome shells. Exact details about how the customization will work is not yet known, but my dream of creating a robot too large to fit into a portal, therefore breaking the mechanics of the game, is unlikely. Instead, a more workable customization would be to create a new paint job or choose from a number of alternative limbs.
Other pre-order bonuses from a multitude of stores and online sites are bound to be announced for Portal 2 before its Spring 2011 release. Point your robot minds to Co-Optimus for all the latest news on the game.