Hey you, wondering tech obsessive. Want a t-shirt with some white outlines that prove you attended CES this year. Then you'd best make your way around to the Engadget stage (between North and Central halls) here in Vegas, because we've got many hundreds of t-shirts to give away all this week. Along the side of the stage we've got a vending machine filled with them. But there's no cash slot. So what do you do? It's not all that complicated. Approach the machine, and you'll be asked to tweet your most beloved gadget of 2012, alongside the mandatory #engadgetces hashtag and a size-code. Seconds later, a freshly packed t-shir