When I was 3, my mom and dad let me watch Austin Powers, three of the movies were out at the time and I had seen them. Mom and dad figured I wouldn't understand what was going on and I didn't... That is until I rewatched the series in 7th grade. I had also found out some of the other kids watched the series at the age I did too! My science teacher even made references to the movie (only 1/4 of the class would get it).
I'm not going to tell you it's a kids movie or it's appropriate either but your kids won't understand what they are talking about, they won't understand the sexual references. But it honestly depends on the type of parent you are, i.e. if you curse around your kid and they know it's bad and they're used to it.