If you find yourself on the Isle of Man and run out of gas you can take the bottle to the Manx Gas depot just outside Douglas and they will refill it for you. You stay outside a big high-fenced compound and a guy who knows what he is doing, wearing lots of safety kit can refill it. You can watch, from a distance. One safety issue that hasn't been mentioned is that liquid gas evaporates in air at a phenomenal rate and if you get your hand in the way whilst doing up / undoing a valve you can get very serious burns from the cold. That is if you survive the landing from your 200ft flight if it explodes. Another refillable make is Gas-it, who exhibit at shows, and Safe-fill bottles. Gas-it do a kit where you can fit a LPG socket on the side of your van which is allowable to be refilled at petrol stations, but the Safe-fill bottle has to be removed and filled as a stand-alone bottle.