Thank you to Amy at Comments from the Peanut Gallery for this information.
If you live in Illinois, here's a new service to check out. The Illinois Secretary of State's office has an emergency contact database. You can list two people to contact in case of an emergency. If you are in a car accident or other emergency and cannot communicate, emergency personnel can search the database to see if you are registered.
I just did it. The whole process took about 5 minutes.
At the end of the registration process, you are offered the opportunity to become an organ donor. If you haven't already registered, please consider doing that as well. A friend's cousin just died while waiting for a liver transplant. Let's face it, if you aren't using your organs, you might as well save someone else's life.