I carry a laminated card in my wallet as well. I've just always wondered, would somebody in the ER bother to fish through all the stuff in my wallet to find it?
The one time I took seriously ill alone and far from home, was in a remote part of West Africa, I was carrying a card with "en cas d'urgence" in bold letters and detailed instructions about who to contact, etc. They never saw it until I came to in a hospital in the capital city and pointed it out to them. Give them credit though...still had my bag, wallet, passport, and all my money intact, and somebody had eventually thought to call the consulate.
ICE on the cell phone is good but my last accident took a heavy toll on the phone. I handed my wallet to the nice paramedic and he pulled my license out and handed the wallet back. I'd suggest taping something to the back of your license.
I've always identified certain contacts in my phone's address book as ICE contacts, but you should carry a "hard copy" of emergency contacts, too. Phones are not always recovered when you wreck, and sometimes, even with a picture ID in your wallet, you are left unrecognizable and admitted to a hospital as a John Doe. Ask me how I know.