Nest is a revolutionary new thermostat from among others, a couple minds behind Apple's iPod. At first sight it's no question that it has a clean and simple design right down to the packaging, just like Apple is oh so well known for. Beyond the cool factor is the brains of it though. It's described as the only thermostat to improve with time. It actually learns how you live and follows your schedule to help you save energy by turning the thermostat up or down automatically. Pretty interesting.
Of course it also offers an iPhone app so you can control it while you're away if you need to. Example, you're getting back into town and want to turn the AC on before you get there. Nest has built-in Wi-Fi so you can actually control it from anywhere inside the home as well, upstairs, down, etc.
It's easy to install to, it simply screws right into where your old thermostat sits. If you can switch out a light fixture, than you can do this.