E.S.

Preparing for my 2013 season of safe and accident-free riding... but in that spirit, I'm also re-examining what I carry on rides.
What do emergency responders need to know about me in the case of an emergency?

Hypothetical: I'm out riding solo and I am involved in some kind of accident, unconscious and possibly seriously injured on the side of the road. (Hopefully not dead). What kind of ID/medical information is relevant and necessary to the good-samaritan first-responder, emergency personnel, and hospital staff?

I currently carry at least my ID but not at all opposed to getting some cheap dog tags with contact phone numbers, blood type info? etc.

Thanks for input.