This project is interesting because it build a no man robot car to drive itself and voiding obstacles.

http://m.instructables.com/id/Android-G1-Serial-To-Arduino/

I like this project because it used everything that are very common, the platform they choose is android and with free software to download from website. This is a powerful project with a limited budget

This is a robotic arm controlled by an android phone, the team also made GUI for controlling the robot.