The Octolively is one of the most entertaining kits I have built in a while. It’s an interactive, tileable LED module that carries eight huge (10mm) LEDs arranged on its 4″×8″ board. Its sensors detect nearby movement using both infrared and visible light, and the LEDs, which come in a variety of colors, respond with eight preprogrammed behaviors you select with a button. You can also use an AVR programmer to program custom behaviors or install firmware updates. The Octolively modules run off 5V DC and can be installed almost anywhere.