Maker fair was cool
My favorite project there was the Brain Bats by Hack Manhattan.
They did this Play Pong using a EEG headset, Arduino and python code!
The reason I liked this was that it was a very simple build up, they had the EEG placed on your for head and ear flip and you could see the concentration level on the laptop while playing. It was a little inaccurate but I beat the computer big time!