Earlier this year I did some development for a hardware designer who has been getting into energy-harvesting. He had a Bluetooth-LE profile miroprocessor runni

Earlier this year I did some development for a hardware designer who has been getting into energy-harvesting. He had a Bluetooth-LE profile miroprocessor running wired up to an energy-harvesting chip, meaning that we were able to build a network of Bluetooth-LE devices that didn't require any power supplies. These prototypes are working (the app is made to render the whole kaboose as a point-cloud) and as far as I can tell, the only reason these things haven't hit the market yet, is timing. He's also not the only designer working on such products - as a result of contact with the LE/Infinergy industry, I see quite a few other startups attempting to 'capture' this space before it launches. So I predict it won't be long until we have such devices out there. I'm already using one of the prototypes to find my keys .. only problem is, I can't use it to find my phone, where the app is installed .. ;)