I had some spare time over the holidays, and decided to break out an Arduino that I had been sitting on for over a year. Since this was my first time playing with the microcontroller, I decided to start with some very simple LED cirtuits and programs.
For example, here's one where there are 2 LEDs on the breadboard, one standard blue LED and one RGB LED.
Video of it in action (don't mind the mess of wires and extra parts on the breadboard... I was playing with lots of different circuits):