Ever lose your wallet? Presumably it would be much harder to lose this one. Woolet is basically a wallet with a Bluetooth tether built in that can be paired with your phone. It has just been funded on Kickstarter with more than a month still to go.
Woolet is a slim leather wallet that comes in two styles. It has a variety of pockets (including a secret one) and some built-in electronics. The Woolet will pair with a phone over Bluetooth 4.0 to alert you if the connection is broken. There's a Woolet app that will pop up a notification on your phone (it barks for some reason, which is dumb) and the wallet itself can sound an alarm if you walk away without your phone.
The electronics are powered by a low-energy ARM Cortex-M0 processor and can recharge as you carry Woolet around. The team is working on both movement-based recharging and body heat recharging. This is probably the most interesting thing about Woolet.
$99 is pricey for a wallet, but it's actually not outlandish if the leather is of good quality. Aesthetics are highly personal, of course, but the Woolet looks okay. I don't think it's unattractive at least. Enough people are into it that the project is already well-funded.