Reading all the suggestions here sparks my interest in an idea I was tinkering with last year after I moved into a big house and I wanted to monitor and control everything through the web / phone app. In addition, I wanted useful stats about everything (a lot were mentioned in this thread). The main problem I was trying to address was building a centralized system that would communicate with devices built on different protocols (Zigbee, ZWave, Bluetooth, etc.) and allow them to communicate with each other via the central controller.I started to work on it, but got caught up deciphering various protocols and have been trying to validate the idea before venturing further into it. I hate the idea of owning several independent systems and want something that's unified - at least as far as monitoring goes. It sounds like there is a need for smarter homes. I would love such a unified system at home. I've also considered creating hardware to facilitate certain use-cases.

If anyone wants to collaborate on this, it would be fantastic! I was planning on making it open-source and free for home use. It wouldn't be a bad idea to simply solve some of the use-cases for folks on HN.