In December 2006, I started playing with the Arduino NG/Atmega8 hardware platform. It's a lot of fun to write software in a Processing-like environment, click a button, tag the reset button on the Arduino board, and see stuff happen on a physical device.
The main reason I picked it up was to work on a standalone DAMMIT/DARNIT like light show. As of December 4, I have a system with three knobs that control various parameters for the display of patterns on 8 LEDs. Soon, it will be triggering lights via solid-state relays. Click through to the image gallery for pics of it.
In October of 2007, I attempted to make a Halloween display using Arduino as the core brains and data logger, but was unable to make it all happen in time. Since then, I haven't really touched it much.