I don't think we have the kind of $$$$ for this idea: I don't know how much the related technology costs, but what happens to all those transmitting tags that go on the shoes of the entrants at the Boston or NY Marathon? do they get thrown away? wouldn't we like to have them? Would anybody here like plot to "borrow" shoes at the end of a marathon from about 80 unsuspecting and fatigued runners? Under the ruse of giving foot massages?