How old is he? My son will be one on June 5. He recently went with us to see Van Helsing. He has also been to see Underworld and Lord of the Rings. The key is to go when the theater is less likely to be busy. If you can go during a weekday when most people are at work, that is ideal. Then he will be less likely to bother people if he gets a little fussy. Also, don't let him sleep for some time before the movie. That way, he may fall asleep during the show. Unfortunately, for Van Helsing, he was asleep shortly before we left so he didn't want to sleep during the film. He got fussy and my wife had to take him down into the entryway of the theater so he wouldn't bother people. Otherwise, he has been pretty good. Make sure you bring food, drink, and some quiet toys for him as well.
Scott
NP: Annihilator - Carnival Diablos