I carry my student id, drivers license, and my UM hospital "Blue Card" (links to medical history and insurance info if they scan it at the UM hospital-- where i'd hopefully end up if anything bad happened). I have a cell too, with phonebook entries such as "Mom" and "Mom Work" saved in it, though my drivers' license has my family contact info on it (student id has local contact info). Hopefully if anything happened, someone'd be bright enough to check my back jersey pockets!