If you're at PAX, you can easily get a new t-shirt to cover your shiny cyborg torso and all of your pneumatic sinews. All you have to do is pre-order a copy of Metal Gear Rising: Revengeance
at the Konami booth, and you'll be rewarded with a t-shirt exclusive to the event. The pre-order will be fulfilled by Amazon, so you won't have to ... go find the booth again in February or something.
We have yet to see a picture of the exclusive item. You'll just have to be surprised (!) at the booth.