Back to the medical info wallet card, 3M makes a self-laminating tag that works great for these cards. It's called "self-sealing laminating pouches for bag tags." I just got some at my neighborhood drug store in the office supply section. You simply peel back the top layer, remove the paper insert, add your own item to be laminated, and then let the top layer go back in place. Lightly press with your hand.... Then you're done. There is even a loop you can use to attach your card to your belt, backpack, whatever.
I've even used these pouches to attach to travel bugs if the tbs have special goals or missions.