Nest

A thermostat designed by some of the geniuses who worked on the iPod, this learns how best to heat your house by monitoring your activities and predicting what temperature you’d like at any given time. Give it a week, and the makers claim it’ll have your daily routine down pat. It has Wi-Fi built in, so you can switch it on or off from anywhere in the world via an app. This has two key benefits: you keep your energy bills down, and you can annoy anyone who’s at home while you’re out by choosing an oven- or fridge-like temp. $249, nest.com.