A few years ago (2006?) my Dad bought a robot. It was really cool and was controlled by a computer. The robot used treads to move and an Xbee to receive commands. After a while it was put in a box and we moved to a new house. This past year I found it again and tried to get it working. The problem is the company that made the computer software that runs it it gone. My solution, an Arduino.
After a few months I was able to send programs to the Arduino that then made the Robot move. I also learned about drivers (chips that turn control signals into motor movements) and how to program with functions. (lines of code that refer to other code, ie if i say do X, then it finds the line of code that says what X is). They save a ton of room.
Now that I have the code for serial communication an Arduino Esplora remote controler isnt far away.