We've been talking a lot this month about the importance of the do it yourself ethic to green technology, noting that the DIY electronics trend is an empowering one. If you'd like to be really empowered, and could use a CCTV system that runs on an uninterruptable power supply (UPS), this is a great project.
The project was designed, tested and built by students Dom and Chris, who posted it on Instructables under the handle ooda55. Special thanks to them for their permission to post it here.
NB: This is not a low-tech project; it requires a solid knowledge of electronics, and especially of relevant safety procedures.