I have also wondered if TSA would allow me to remove my prosthesis (I could wear shorts) and have it xrayed on the conveyor belt while I just hop on one foot through the mag (I do this at home all the time - well, without the mag part). Then no alarms would be set off, and I could just put my leg back on and go, without being touched. I don't know whether I'm gutsy enough to try this, but it's a thought I've had.