"Great Gadget"4.0 starson by cspike2
Pros: It looks great, has an intuitive interface, it's simple to set up and use, and WIFI built in means you can control it from the a computer or your smart phone.
Cons: Pricey, but it seemed comparable when I priced other thermostats with WIFI capability.
Summary: I saw the NEST thermostat mentioned on CNET last year and checked into it. They were sold out so I entered my email to be notified when they were available again. I got a notice that they were available and decided to take the plunge. The ability to control the temperature from our smart phones was one of the big selling points for me. You can be heading home, check and adjust the temperature in preparation for your arrival. The learning function is nice when you are on a regular schedule, but it still tries to learn even when you aren't. It is expensive, but when you check the price of other WIFI compatible thermostats, it's about right. And it can be modified, just like a smart phone, so new functionality and enhancements can be added in the future.