Nest Thermostat

You can now buy a Nest Thermostat through Google Play. Price is the same as other retail outlets — $249 — and it'll ship in 1 to 2 business days, Google says. And for every thermostat sold today, Google will plant a tree. Because Earth Day. It's also available in the UK for £179.

The Nest Thermostat is a "learning" device that connects to the Internet (and other Nest products). It's got a 1.75-inch display, controlled by a metal ring on the outside of the thermostat. Nest learns your temperature preferences, when you're home or away, and is aware of the outside weather, and adjusts itself accordingly. It's not a cheap device, for sure, but promises to pay for itself in savings.

Not available still is Nest Protect, which was pulled from market because of software issues with the combination smoke/carbon monoxide detector.