I was very impressed when I saw HiTechnic's Lego segway. I was very excited to find out that Android devices could be programmed to interface with Lego robotics with ease using App Inventor. Naturally I decided to build a robotic segway remotely controlled by my phone. This required two programs: one on the NXT to balance the bot and receive instructions, and another on my phone to convert accelerometer readings into text messages that told the robot what to do.
As much as I'd like to take credit for building such a cool robot, the truth is I did very, very little. Basically, I built the segway shown on HiTechnic's website, downloaded their program, and modified it to received bluetooth text messages. I had to find a "text to number" block to convert what I was receiving into usable values (App Inventor doesn't like to send NXTs numbers for some reason). I don't know who created this block, but whoever you are-thanks. To send the messages I downloaded and modified Liz Looney's ShinyLegoNXT to create a simple interface capable of connecting to my robot.