I'm in the process of putting this page together so currently it needs a lot of work. I'm in the idea phase of development and I'm just scribbling down my ideas. So this page may become a bit incoherent until I get the wording correct (or as my English teachers used to note "ackward phrasing"). The basic premise is to create a monitoring system that will send data back to a PC for recording and analyses. I intend on using a BASIC Stamp I/II, PICStick (etc), Motorola 68HC11, or other such single chip setup. The intention is to combine the use of a simple BASIC programming language, a single chip CPU and my electronic knowledge that I learned in college (I'm trying to keep my skills usable, I design computer networks for a living). The processor will have to determine if a door is open or closed (reed switch), if the compressor is on or off (ferrite core wrap and sent to an adc) and the temperature in the refrigerator and freezer (Dallas onewire chip, DS1820) and an RS485 interface (to hook up to my HCS II). I'll probably use RS232 initially and then attempt to add the RS485 networking code. This will probably preclude the use of the BASIC Stamps as they do not permit the use of assembly language (to trim memory usage).
One of the simplest home appliances to monitor is the kitchen refrigerator. By using a small processor with built in memory and storage and a number of sensors such as a Dallas 1820 temperature IC, digital IO, an ADC and a network interface to RS485 and you've got a simple way to monitor the operation of a household refrigerator/freezer.
The Dallas onewire IC's are great in that you can hook multiple IC's to the same wire and get temperature reading from each IC. They can be up a good distance from the previous device and still work.
Oh oh oh, I got an idea! Many people will open the 'frig door and stare inside aimlessly looking for "something to eat" (we all know there's never "something to eat"). How about a web cam that is internal to the 'frig. We'll finally know if the light is on without opening the door. We can use IR to view what is inside and we can see it from anywhere on the internet. Hmmm, maybe this is not such a bad idea after all.