I've heard there was a tour, but I can't find anything about it. Just the gallery itself. I'll be in Berlin in November.
Not sure if there is a tour there or not, as it is just the left-overs from the wall that people keep painting. Perhaps it is part of one of the biking or walking tours in Berlin, but you would have to check their websites to see if it is included. Here are the reviews on Trip Advisor from others who have visited. http://www.tripadvisor.com/Attraction_Review-g187323-d191041-Reviews-East_Side_Gallery-Berlin.html
I have been on a bike tour that went to the East Side Gallery. The link is below. It was a great tour. http://fattirebiketours.com/berlin/tours/berlin-wall-bike-tour