This rendition of the portable Xbox 360 uses a HDTV strapped to a guy with a 360 and I would assume a wireless adapter on it. They could be using a laptop with wireless internet so they could go anywhere. It looks to be powered by a generator, which knowing the power the 360 and that TV uses, might last about 10 minutes. Whatever the case I guess these guys could take a walk around the block while getting some frags in good ol' Slayer.
The best part about this rig is the ability to go online and sign in to Xbox Live on the go. Now considering how easy this mod looks, anyone could do it. Just imagine taking this thing on the bus, or maybe the next time you "Jump In" to Halo 3 Lone Wolves you might be playing somebody walkin' their dog.