I forget the details of why I decided to buy a Nest thermostat (probably to do with the opacity of programming the damn things and constantly having to adjust them manually: http://walkitout.livejournal.com/1075502.html And indeed, I adjust the Nest 'stats a lot less. Also, I love love love being about to tell the house to warm up or cool down on the day we return home from a trip but hours in advance of our arrival). We also experimented with a wifi garage door opener that you can access through a keypad or a phone app (mixed feelings about this: super awesome to be able to let a repair person in when you can't be there Right That Minute. Super UN cool that there has been an intermittent mystery open problem that forces us to lock it closed more often than I would prefer).
More recently, R. (I'm sure he regrets this) mentioned someone at work looking at who was at their front door -- while they were at work. I thought, cool! We should get cameras. But then I thought, wait, where would we mount them? I don't want to muck up the look of the front of our house.
Which led me to connected doorbells. There are a couple (I've ordered the SkyBell) that wire into standard doorbell wiring, but also will let you look through their camera (whenever you like!), alert you whether the bell is rung or not, based on motion sensor, infrared for night time -- and all through your phone app.
We have a slight problem. The doorbell is mounted in a place where the SkyBell might not fit. So we shall have to see. But if you're wondering what idiots are participating in the Connected House part of the Internet of Things, apparently I am one of Those Sheep.
ETA: If you are wondering, no, we haven't gotten into any of that control-interior-lights-TV-etc. using-motion-sensors stuff. If you have, I'd love to hear the details.