The Nest Learning Thermostat, part of Consumer Reports' current testing of programmable thermostats, has been hailed as one of the smartest, sleekest energy-saving gadgets on the market, if also one of the most expensive. The $250, Internet-ready device, which some have dubbed the iPhone of thermostats, can supposedly divine your heating and cooling preferences and then adjust your home's HVAC system accordingly, savings you hundreds of dollars each year. Today, its manufacturer announced several enhancements that it says will make the Nest even smarter.

The first upgrade is called the 10-day Energy History view, which allows new and existing Nest owners to see when their home's heating and cooling systems come on and off via a computer or smart phone (shown). Active heating and cooling time periods are represented by red and blue bars across a 24-hour timeline. While this features doesn't improve the Nest's energy-controlling intelligence, per se, it makes it better at communicating the savings to you. And, as they say, seeing is believing.

Nest's other major upgrade goes by the name Airwave, designed for homeowners with air conditioners. Since air conditioners remain cool after they stop running, Airwave will automatically activate your unit's internal fan to distribute this cool air when the unit powers down. That seemingly small measure can save you up to 30 percent on cooling costs, claims Nest. The company also announced a revamped backplate and wire connectors that it says will make installation even easier.

Check back in for updates on our testing of the Nest, along with the other couple dozen programmable thermostats we're evaluating by brands like Honeywell, Lux, and Venstar. And see our programmable thermostat buying guide for general shopping advice.