After Tony Fadell first wowed us with the Nest, our own Chris Ziegler took a stab at installing one on his own. And now, the programmable thermostat's internals have been revealed thanks to the folks at Sparkfun. Disassembly begins by removing the circular LCD, revealing a Lithium-ion polymer battery that rests on a metallic RF shield, which protects the motherboard. The Nest's motherboard is neatly sandwiched between two of these protective RF shields and is packed with silicon and antennas — it's got ZigBee, WiFi and an ARM Cortex A8, to name a few. ZigBee support is a particularly big deal — something Nest hasn't talked about so far — because it suggests that we could see the device integrate into a broader ecosystem of ZigBee-compliant home automation and energy products (think switches, dimmers, controllers, and the like) down the road in a future firmware update. If you're interested in seeing more pictures and details of the teardown (which, let's face it, you probably are), hit the source link below. And if you happen to have a Nest of your own, Sparkfun says it only took minutes to reassemble. So, what are you waiting for?