I am a software engineer by trade and also a rather skilled and well rounded (residential) builder with a special interest in wiring. I have rewired my entire two-unit house, panels included and seen it all.
In the course of home remodelling, I was wishing to be able to control every single electric control on every circuit in my house remotely using an Android app. To make that possible, I would need every single switch/thermostat to be upgraded into a relay and have cat5 cable run alongside every Romex cable to each control on one side and into a PC (or some other cheaper form of a CPU hosting device with a modem) which has a static IP online, on the other side.
Of course, that is a huge project, whose biggest parts would be making relays that can be controlled from a PC and writing software to control it all, web services, mobile app etc. So the first step in R&D would be to actually make something like that -- unless, of course, it exists already.
Is it possible to buy a relay that, on one side controls a regular 110V residential circuit, and on the other can be flipped using a PC?
A residential feature like this could be used to, e.g. report and control temperature at home remotely, turn the heat on 30 min before arriving home etc. You could even mount a web cam and watch your pets remotely.