So in our home we have this very old Honeywell thermostat and my dad suggested replacing it so I have been shopping around a bit. I am VERY intrigued by this Nest thermostat thing but have never met anyone who has it or has used it. I am all for saving money on energy and apparently that's what they claim to do, but they are really expensive! Does anyone here use one or know anything about them? I want some feedback before I commit to a purchase like this.

When it comes to thermostats there are all types and prices .Any programmable thermostat has the ability to save energy.Where are you located, what type of equipment does your thermostat control,how well insulated is your home.

The Nest is like an i-phone: very easy to use but expensive. I'd say it's worth it for someone who doesn't want to have to learn about their HVAC. It's only $100 more than a wi-fi Honeywell, which won't program itself like the Nest.
For someone willing to invest a little time on programming their thermostat, Honeywell has them as low as $30. With that one you can save almost as much money.

I've put in hundreds of programmable thermostats, though, and I'd say less than 25% of the occupants bother to keep a money saving program active. The older ones were always losing their program... whenever the batteries died, or the 24V power supply was lost. Daylight savings time also messed up the programs. Nowadays they keep getting smarter, but Honeywell hasn't gone very far toward "intuitive" user friendliness.

I installed a Nest in my son's home in Nov.. He loves it. When he is on the road he checks his temp and can turn it up before he returns. Says he can't live without it. If there is a HVAC problem in his house it alerts him and it can learn his heating and cooling patterns without programing it. He paid a little less than $200 for his at Lowes

I have had one since April and it is a mixed bag. If you are out of the house during the day, and can locate it where it can 'see you' when you are home, it will save you energy not only doing programmed setbacks but also by automatically setting back when you are not home (unless you find this annoying, or have temp sensitive pets and shut that feature off). For driving simple systems, like single speed gas furnaces, with fast thermal recovery (for when you come home), I think it would save you money and be 'fun'. For a vacation or second home (with wifi) it would also be nice (but cheaper options exist).

I have a ASHP with aux backup, and find that the control algorithms for multiple stage systems leave a LOT to be desired. They will presumably fix that eventually (there are regular, automatic, software updates to the unit over wifi), but in the meantime, I am a little frustrated. I am currently spoofing my nest by giving it the zipcode of a warmer location, to limit aux calls, due to limitations of the built in lockout control....first world problems.

So, simple HVAC system and want to have a fun 'early adopter' experience...go for it and you might even save some $$ and energy.
Complex, multiple-staged system that has less benefit from setbacks (HP) or slower recovery (HP or radiant)...give it a miss.

I live in Minnesota, or as its candidly called MinneSNOWta! Very cold time of year we're in. My house is pretty well insulated I would have to say, and the equipment has all been updated within the last 5 years. I'm definitely willing to spend a little more it it means I will have a long term return. I've talked to the guy at my local Lowe's. He gave some good advice and highly recommended the Nest like some of you here. Thanks everyone for your helpful info and suggestions!

If your a gadget freak with a highly variable schedule (or just can't be bothered to program a 5+2  or 7-day programmable thermostat to your liking) the Nest is going to be your cup o' tea.  It's a significant up-charge with no performance advantage over standard $50 or cheaper programmables, if you're the type who can "set and forget" a progammable thermostat to match the rhythms of your daily/weekly schedule.

Nest isn't the only net-widget thermostat out there though- they're becoming ubiquitous, for better or for worse.

Ecobee is my choice for WiFi stats. They have a basic model and one that will take care of multi stages of heat, aux. lock out. I am able to do some trouble shooting remotely and the stats email me if maintenance or service is available on one of my customer's appliances.
They even monitor usage and convert data to Xcel.
We've been using their spreadsheets the last few days to sort out a customers high energy bills.