If they had one I could use for my son that I could track with GPS or something I would consider it. Hell, I would even put one on my wife because it would be easier to see where she is than ask "where are you" and get the useless response "Um I think I am near starbucks?"
But just for location, not sure about using it as a credit card also. That just encourages someone to cut it off me and take it.
