The Nest is the first thermostat in almost 60 years that's designed in an entirely different way. That's since the T-86 Honeywell came out in 1953. The Nest was designed by former Apple executive Tony Fadell in brainstorming sessions with several other technology experts. It has a round LCD screen that's orange when it's heating and blue when it cools. To set the temperature and perform other functions, you just turn the wheel. It has a Wi-Fi connection that enables you to control the temperature from afar with a smart-phone app. The developers have designed a product that "learns" as well. It looks for patterns in the adjustments you make so it can program itself. For a week's time, it will automatically adjust heating and cooling if you aren't there. It also has built-in activity sensors that detect when the house is empty and doesn't r equire as much heating or cooling. USA Today's Edward Baig notes that at $249, it's expensive in the world of thermostats, but its makers say it pays for itself in two years through energy savings. If Nest is operating at what it considers to be an ideal energy-saving temperature, a green leaf appears on the screen. Changing the temperature even one degree can cut energy costs by 5 percent. According to Time, it works in most homes and is supposed to be as easy to install as a light switch. It uses a lithium battery, which is supposed to last as long as its five-year warranty. When the first production models sold out at Best Buy and on the Web, the $249 units were selling on eBay for up to $899 each.