I think I just found a new people-watching side hobby. Next on HN: Burgling across Brooklyn as hipster keychains "pic-pocketed" en-masse...
I'm really looking forward to when I get the time to rig up my door so I can use my yubikey instead. Much easier than all the metal keys I have to carry around now, and much less damaging to my pockets and belt-loops.
I've decoded keys that I've seen people carrying on rings on their belts (and, in many cases, the pin values are stamped right on the key). I don't carry keys where people can see them, but I'm a little bit paranoid. With the advent of this service it probably pays to be a bit more paranoid, since somebody could take a picture of your key, send $5, and get a copy w/o knowing anything about pins and tumblers.