It is wise to be spontaneous and milk opportunities for goofy fun for all they're worth. It is equally wise to know in advance the locations of nearby playgrounds, ice cream shops and children's museums, along with hospitals (ideally with a pediatric ER) and 24-hour drugstores. Smart-phone apps like Yelp's can help you find what you need without your searching the entire Web. And for children's museums, try the Association of Children's Museums.
Next Don't Be a Dictator