I have had similar problems w/ my dd at storytime (she's 21 mo.). She likes to stand up and walk around during the storytelling- she also went through a phase where during quiet moments she would shout, "Pee pee! Poo poo!" (she had just learned the words.) It was very frustrating. I didn't want to stop taking her, because she LOVES storytime, so what we began to do was this: a few moments before storytime, I would explain to dd that we were about to enter storytime, and that it was a special time for her and the other children along w/ their mommies/daddies. I would tell her that it was important to respect the other children, and that we could do so by using soft voices and sitting/standing in one spot. Once inside, if her behaviour became disruptive to the others, I would explain to her that she needed to stop running, shouting, etc. so that the other children could listen. If she continued, we would step outside for a moment, then return. If she continued after that, we would leave. At this point in her life, I don't harshly reprimand or criticize, because I believe that expecting a curious toddler to sit still and be quiet is a pretty tall order. We would always try again the following week. She has begun doing much better at storytime, because she does not want to leave, but sometimes we still have to, esp. if she is tired or compromised in some way, like teething. It sounds like your son is very excited and stimulated by the experience, which is not necessarily a bad thing! I know how frustrating it can be, though! Good luck!!