In the episode in which Bulma, Goku, and Oolong are camping out in the desert, there is a scene in which a nude Bulma looks out the window, and glare covers her bare breasts. Contrary to popular belief, this scene is not edited for the dub. The glare is there in all versions, uncut Japanese included.
Goku is 12 years old at the beginning of Dragon Ball. He tells Bulma he is 14 but later confesses he didn't know how to count properly at first.
In addition to the 153 episodes of the series and the three movies, there are also two "lost episodes." These are educational films starring the characters about traffic safety and fire safety. These were never released in any shape or form in America, however they are available as bonus features in the Japanese Dragon Box collections.
Goku is based on the Sun Wukong, the Monkey King who is a Chinese monkey god from the folklore story 'Journey to the West'. like the Monkey King, Goku has a flying cloud used for transportation and a magic staff that can extend as far as he wants. Also the Monkey King's name (when in Chinese characters, but read in Japanese) spells "Son Goku".
At the 21st World Martial Arts Tournament, Master Roshi disguises himself as Jackie Chun. The name is a (rather obvious) parody of real-life martial artist Jackie Chan.