RoadID sport wristband. I figure, this way I won't have to worry about forgetting my ID (not that I was ever particularly stressed over it). Now, I can just kick myself for forgetting to donne the Road ID!
I researched what information should be included, and settled on emergency contact infomration and some basic medical information. In some online forums, I learned that drug allergy information and medical history of any cardiorespiratory conditions are very useful pieces of information for EMT's and medical personnel. Blood type is nice to know, but the chances are if you're losing blood that needs replacing, they'll just do a quick test to determine your blood type on the spot before checking your medical alert information, anyway. Still, there was room on the last field, so I added it.
The basic information I included were name, birth year (for age determination), home address, emergency contact (home and spouses cell), NKDA (no known drug allergies), asthma (usually mild, but I have a history), LPR (I have a low pulse rate even when I'm not in shape-low enough they won't let me give blood sometimes), and blood type.
I'll be wearing this whenever I go out for a run or a bicycle ride, so if something happens, as long as I don't lose my right arm, they'll know who I am and who to contact.
I wouldn't have thought of it, but about two years ago, my wife was walking at a local county park, and a witnessed a cyclist crash when he hit some gravel while speeding down a hill around a curve. He slid off the road and would have gone off a cliff if it were not for a guard rail. Fortunately for him, he was conscious and she loaded him and his bike in the car and took him to the emergency room. He could easily have been more seriously injured however and nobody would have known who to contact.
So, if you run or ride on the roads and/or trails where an accident could befall you, however remote the possibility, you should consider having some kind of ID and emergency information with you. RoadID is a good option, but if you look around you can find others as well, or at the very least carry your driver's license of ID card. It might help early responders save your life and notify your loved ones.