For guys that already have these, there is also an app that you can run on a windows box that adds some features to the thermostat. There is a free version that just does the basics and then there is a premium version for $13 that tracks when your HVAC is running, downloads weather off of the 'net, and will also allow you to have a circulate setting on the fan that will bump just the fan on and off occasionally.
http://www.setyourthermostat.com/tour/

Thermostat software - Set your thermostat from the comfort of your desk

I bought a filtrete thermostat and installed it today. The hard part was that I had to upgrade my thermostat wire from a four conductor to a five conductor wire. I also bought the windows app from Thermostat software - Set your thermostat from the comfort of your desk. It makes setting your program much easier, and the other features are nice as well. I like the fact that it keeps a log of when your heat and AC runs. It's also cool that it downloads the weather (temp, humidity) and keeps that in the log too.

OK, the geek in me would like the part about storing the run info and the weather data...

also compile outside temps., wind speed, rain, and heating/cooling degree days and then run your multiple regressions on that

for more geeky fun look into canonical correlation analysis...

Installed and up & running with my Nest. Took just a few minutes. Very slick!

The Nest has been improved! Continued development is the reason I bought into this thing and is invaluable to me.

http://www.nest.com/2012/04/05/nest_thermostat_software_brings_more_info_savings_ access

http://www.nest.com/wp-content/uploa.../04/BLOG_1.png

I'm digging it! One thing I haven't seen is text or email alerts for out-of-range temperatures. Seems odd that they aren't doing that now. I'd like to know if the temp in my shack drops below 40 degrees while I'm away.

post the IP address so we can all "affect things"!

Just got a NEST for Father's Day, very cool. Took about an hour to take the old one out, spackle a few holes, paint match with existing wall paint and mount and program the NEST. My wife thought it was a cool geeky Father's Day present. She'll think twice when I'm raising the A/C temp from Europe!