Over at the Make blog, Marc de Vinck has a charming video that shows you how to do a simple Arduino project.
Arduino is a tool for making computers that can sense and control more of the physical world than your desktop computer. It's an open-source physical computing platform based on a simple microcontroller board, and a development environment for writing software for the board. Arduino is open source! In addition to the genuine Arduino, resistors, buttons and other goodies, we've also tossed in our best selling Making Things Talkbook.