My arduinomega based linefollower R.A.L.F is finished. Even made a video of him following a line on the floor. I ran out off electrical tape, that's why there is some duct tape too there. He sees the world through three Pololu QTR1RC sensors mounted on some breadboard, with a ribbon cable for connecting it to the Arduino Mega(I know it's oversized for something with one serial line and three input sensors as the only devices, but it was the only one that wasn't in some other project). The motor controller is a Pololu Qik 2s9v1 Dual Serial Motor Controller. I can highly recommend it. It's very easy to work with and can handle 4.5V - 13.5V, with a continious output of 1A and a peak of 3A.