The MicroID Rescue Collar is just a glorified regular collar. It includes a small compartment with a USB flash drive. Plug it in and fill in all of the information, so if your pooch gets lost, the finder (given that they actually own a computer) will be able to return the pooch because of the included information. It is the same thing as the standard metal dog ID, except it requires more work, effort, and costs more. It would be a good way to hide some files, though.

Product Page [Via Get USB info]