Recently our founder, Nat, left one of these on my desk; he left one for everyone in the office, in fact. It's a product simply called Tile, and it's a pretty amazing invention.
In short, you can attach a Tile to anything - keys, computer, tablet, bag - and it will help you find those items should they get lost. Tile works in two different important ways:
1: An immediate locator. If you lose your keys in the house, for instance, you can use your phone to play "Hot Warm or Cold" from your screen. Conversely, the app can make the Tile chime until you find where the sound is coming from. Never lose anything in your home again.
2: A distance locator. This is how I use my Tile; here in Portland, bikes get stolen all the time, so I attached mine to my bike. Here's the great part, not only can I see where I last had my bike, but if any other Tile user passes near my bike (assuming I report it as lost) I get a signal that tells me where the other user was in location to my lost item. In other words, other users can effectively find my lost item without even knowing I am looking for it.
If you are anything like me, prone to losing things, Tile is a really great product. Thanks, Nat.