When we bought our flat, we found the heating had no thermostat (how on earth do people live without one? I'm not sure...). Since I had an Arduino handy, I thought I'd make one. I got a handful of Maxim 1-wire temperature sensors, a few meters of Cat-5 cable and set to work. Here's what I made:

Homebrew Central Heating Thermostat

Back in August,  möp, möp! wrote an article describing how he'd hooked up his washing machine to his home network so that he could see when the laundry was done.

Here's a bit of a roundup of some simple power supplies. These designs are really just the basics; they're all a way to make a large DC voltage into a smaller one (eg. 12V into 5V, or 5V into 3.3V). These solutions are generally good where the application isn't super-sensitive to the output voltage, or indeed the "smoothness" of the output. Unless you're very careful about component choices, these are only good for low current applications.

Pulse Width Modulation (PWM) is a great way of controlling lights, motors and servos. By cunning use of PWM, it's possible to control the amount of power a device receives, or the voltage of a power supply, or the angle of the rotor of a servo. PWM is so useful that there's a great deal of support for it in various products.