A Humanoid Robot called Androvie from Vstone won the Robot Marathon in Japan early December 2011.
He finished 42.195km in 45 hours, 48 minutes and 7 seconds fully autonomous, using an Android Smartphone on his head to follow a line with image recognition.
We all know, that Line following robots mostly use light sensors to trace the line and wheels, but using a walking bipedal robot with many servos and Android OS with image recognition is pretty new. This means, that the robot can not just sense the line, but actually see it.
The robot sports 22 Degrees of Freedom, Bluetooth, 2 Nickel-hydrogen batteries, 1x 2-axis gyro sensor, 1x 3-axis accelerometer and can connect to a wifi network by itself.