Which I don't think exists yet as a consumer product. But super cool! I was sort of hoping for a directional display, but a warm/cold beeper is okay, too.
Then today, I learned about this:
Also, doesn't exist yet. It has some really great characteristics: it could work over much greater distances (since it uses Bluetooth and all subscribers phones), and doesn't require additional hardware to be attached to the phone (which, honestly, if you need one of these things, you are at great risk of losing). But here's the truly appalling part about Tile: the Tiles cost $25/each and have to be replaced annually.
For realz. Essentially, you pay $25/year per item as a weird form of insurance against loss. No way in _hell_ should anyone be paying that kind of insurance for any of the usual suspects (keys, even wallets); you'd be better off spending your money on a few rounds of cognitive behavioral therapy to help you figure out a way to get organized enough to Stop Leaving Your Shit Everywhere.
Or, maybe, join a 12 step group or something, if substances are involved. (Which seems likely, since that's how the advertising is aimed: Tile everything you might lose, "Then get on with the fun."
But you know, YMMV.