Napoleon Dynamite is an unusual film. Although there are a few ongoing series of events that keep the film moving, it's really a nostalgia/mood/oddball humor piece. Napoleon and most of the people around him seem to be living in 1982-84. Their clothing, hairstyles, and communication are all characteristic of that period. On the other hand, the director clearly indicates at several points that the action is occurring in 2004-2005. Napoleon and the people around him are living in Idaho, which is the only possible reconciliation. Maybe we can buy the idea that Idaho is literally about 20-25 years behind the times. A better interpretation is probably that early 80's nostalgia makes it fun to fill a 2004 plot with characters dressed in 80's regalia. The result works. Although events move slowly, the viewer is rarely bored. It's a lot like moving through a really interesting museum. You're in no hurry to leave.
The best part of Napoleon Dynamite is the title character. Everything about him is hilarious. When he comes on screen, you are simply waiting to laugh. Jon Heder plays Napoleon and inhabits the character with great success. If the movie had nothing more than Mr. Heder expressing the thoughts of Mr. Dynamite, it would still be worth watching. In fact, that's just about what you get, except that there are at least two other characters in Napoleon's own family who are almost as interesting. Uncle Rico and brother Kip are nearly as much fun as Napoleon and could probably serve as building blocks for their own films. Heder will be offered more geek roles after this one and should refuse. His masterpiece is in the can. It's time for him to move on to something else.