You can see a really cool Segway robot that goes by remote control, (in which part of it uses an Arduino board) Autonomously, in any direction at any speed. There's a video on youtube here's the link
http://www.youtube.com/watch?v=MVS-XFs6unI If you have a question or comment, please leave a comment on youtube.

That looks really cool! I love self-centering bots, for some reason they tend to bring out the nerd in me. Out of curiosity, would you mind posting the code on here so I can take a look at it? I'm always curious as to how others code their bots.

The code is very long and I used all eight cores of the propeller processer (eight programs). I have an explanation of what i did on my website
http://www.art-of-invention.com under the robotics tab.