Find your Keys with your Phone
Good article here with a round-up of even more gadget-based solutions for finding your lost keys.
The advantages of a battery-powered solution include a separation alarms (so you won’t walk away from your keys in the first place), and some great-looking Bluetooth apps for locating your misplaced keys, even if they’re just down the back of the sofa. Several of these gadgets will emit a homing sound, similar to Find My iPhone, which is often all you need.
On the downside, they’re moderately expensive, require maintenance (battery or whole gadget replacement), and need to connect with other devices for tracking to work beyond bluetooth range (10m).
But these are all very clever solutions to a common problem, and I predict at least one of these start-ups will get acquired this year and suddenly become an everyday part of our lives.