Magic Wand
This is a light wand that uses a 60 LED strip and a small embedded microcontroller to control the LEDs. I have included the Arduino source code with the thing files.
A demo of the wand operating can be found here: http://youtu.be/sn-klYeQRcA
You can programmatically make any light sequence you want by altering the source code.
This uses 3 AA batteries to power the LED strip and the microcontroller. The battery compartment is printed inside the handle of the wand. The battery door is held in place by a single M3x20 screw.
information on how to install Arduino for the Trinket microcontroller can be found here: http://learn.adafruit.com/introducing-trinket/setting-up-with-arduino-ide
Information on how the LED strip works can be found here: http://learn.adafruit.com/adafruit-neopixel-uberguide/power
Trinket Microcontroller can be purchased here: http://www.adafruit.com/products/1501
LED strip can be purchased here: http://www.adafruit.com/products/1138