I love visiting Dr. Edward Cheung's web site, at least the HA portion. :-) He always has interesting hardware that he has built. That's right he builds microcontroller boards to interface to things (how's that for a technical description :-). He has a power line monitor he built (cool!) and he's updated his Municipal Water Meter Monitor page. He had a new meter installed and it required a different, more sensitive sensor to measure water usage. I think you will find his explanations, diagrams, code and schematics easy to understand if you have an electronics background (yes you need to be able to handle a soldering iron). Yes I'm a hardware geek though I know software as well.