Couple of days ago I wrote a post about how I got started with an Arduino UNO and wrote my first Sketch (a Sketch is an App written using Arduino IDE and and uploaded to the board via Serial). Click here to read it.
The Starter Kit had an LED attached to a a very small PCB with four pins. Picking it up I realized it was an RGB LED with three resistors printed on it. Neat!
I knew what I wanted to do with it.