There are also lots of phone apps, many free. There are USB pendants and wallet cards in addition to bracelets at some places.
One caveat is to find out before you buy what you can put on the device. Some will accept digital copies of your scans and documents. Some have only a limited format into which you can put a few things like allergies, and you may not be able to put in as much as you want to.
Additionally, you may want to know the format that documents are stored in. Some may be PDF files, which are easily read by most computers.
I will still carry paper copies of anything really important because there may not be a computer available in an ambulance or on the floor of a store.