While adjusting his own posterior side armor, TK420 (left) steps back after assisting TK151 with the adorning of the backpack. These backpacks can be quite functional: Stow important gear in a comparment in the pack (wallets, ID so you can buy beer, etc.) If it's not an obvious compartment, folks aren't going to try to get into it. I've carried items in my O2 cannister (the ends are pressure fitted only) but have a constant concern of someone grabbing the cannister, 'cuz it looks cool!
Photo by TK861