There are a lot of LEGO Mindstorms robots out there, but I finally found the best. Nic_1 is a Johnny V impersonator that detects the direction of sound and follows it. Detection is accomplished by calculating the cross-correlation of two audio signals from the binaural sensor. The data is used to estimate the phase difference between the them. (Videos tracking Kelly Clarkson included!)

I can’t wait any longer for LEGO Mindstorms NXT in August. 32 bits, servos, and mics, oh my!