Read the second link for all the tech-details. These things are pretty amazing:
durable, cheap, crypto-secure, and can be mounted on a key fob, ring, watch, or
other personal item...whatever thing it is that you, personally, have spent
your whole life learning not to lose.
When I started learning about everything they can do, I was amazed that they
weren't more widely known (although there are more than 85,000,000 of them in
use around the world.) Slashdotters looking for new toys to tinker with and
code for would do well to look at this platform. It's ripe with options,
capabilities, and possibilities.