I carry some form of ID. Usually my DL or my military ID. One is as good as the other. Plus my mil ID has my Geneva Convention Category in case things get really weird.

I also wear my dog tags. They have my blood type and a red tag saying I'm allergic to penicillian.

Also, I have my cell phone with my home phone programmed under "home" the idea being if all else fails and they need to find someone to scrape up the pieces, they might check my phone.