As manufacturers start to figure out the long term benefits of smarter thermostats and a generally connected home, it's going to become important to measure more than what's happening in the room with the thermostat. While that is usually a primary location in the home, if you have bedrooms or hallways that are traditionally warmer or cooler than the primary living space that could be important information to collect. The Ecobee3 smart thermostat solves this by relying on multiple remote sensors, which you can place wherever you choose. In their demo at CES this year, you can see the starter kit includes a single extra sensor to help you determine how many you might need to measure your whole house.
The best part about these remote sensors is the way that they can be mounted just about anywhere, and the Ecobee3 thermostat or app will help you see exactly what is happening to the temperature throughout your house.