Penicillin has an excellent chance of making me end up dead. So... as a result of that, and a trip solo to go cycling and hiking in the Appalachians, I got the RoadID. Fiancee, parents, MD numbers are on there, as are blood type and PCN allergy. Seems like a simple step to take... I do bring along drivers license and insurance card, though, for the kinds of emergencies for which one is conscious.

FWIW, I think the wrist or neck is more likely to be found than the ankle, but any of the above help.