For this assignment, I dissected a toy helicopter. The helicopter couldn't fly anymore since the part keeping the rotor blades straight broke. Here is what it looked like before I took it apart:

Removing the cover and the base to reveal what's inside:

What's inside: LED, battery, motor and gears, and circuit board.

All of the parts, organized by type:

I re-purposed one of the motors using an Arduino Uno:

Here is the motor in action: http://www.youtube.com/watch?v=QPbonplY1lE