Receiving a thermostat as a gift is a bit like getting socks for Christmas: Sure, it's useful, but it'll never top someone's wish list. The Nest ($249) is no normal thermostat, however. This "smart" thermostat lets you control and monitor your home's HVAC system from the comfort of your computer, smartphone, or tablet. It learns from your habits and routines as well, so it knows when you're away from home -- and it turns down the heat accordingly. It might make a great present for the home-automation fan in your life.