Tethercell's "re-imagining" of your run-of-the-mill AA battery, is more of a remote-controlled battery and is currently seeking funding on Indiegogo. Of course, we wouldn't write it up if there wasn't an app, and with the app there's actually quite a lot of cool stuff you can do with the Tethercell. I saw a prototype at the annual ShowStoppers event (held during CES), and it worked well and looked like a winner -- if it gets funded, of course.
Besides a simple remote control, the Tethercell can be programmed to turn on or off at certain times, control several devices at once, and even warn you when batteries are getting low.
The Tethercell hardware (still in prototype phase) is clever, as you take a AA battery out of a device, put a AAA battery in the Tethercell, and because it is the size of an AA, you can simply drop it in and it works. Even if you have multiple batteries, it fits just fine.
But first the inventors need to get funding, and they are asking for US$59,000 to get started. Each Tethercell should cost about $30, and I was told buying more would make them cheaper per unit. While it's not a real product yet, Tethercell has so far been one of the cooler items I've seen at CES this year.