Nathan VITAband is my solution.
I have multiple contacts registered, my health insurance carrier, my blood type, allergies, etc. It also has cash loaded on it - so when I stop at convenience stores, I really don't need to have my ziplock bag wallet with me all the time. And if I use up the money I have loaded on it, all I have to do is log on and add a bit more. Simple.
The VITAbands come in multiple colors and sizes - check them out here. I'm thinking of getting a few for stocking stuffers this Christmas...