Trey Parker and Matt Stone originally wanted the role of T-Rex to be played by a plus-size stripper known as "Eartha Quake", but had to find someone else when they discovered that she had recently lost all her excess weight.
When Lisa is looking through the video store, under "Epics", the videotapes are as follows, in this order: Birth Of Jesus; Jesus Of Nazareth; Jesus The Healer; Jesus Of Nazareth (again); Jesus Scissorhands; Pulp Jesus; The Good, The Bad, Jesus; and Raging Jesus.
In India, the word "Choda" is colloquial for Fuck in many languages including Hindi. The side-kick is called 'Choda Boy', which would be "Fucker" in Hindi, and completely in line with the Orgazmo theme.
In the scene in the video store (the one when Lisa finds out that Joe has been doing porno films), the first shot shows the top row of a movie section. Contained in this row are all movies by Troma Studios. Troma owns the rights to Trey Parker's first film, Cannibal! The Musical (1993) (aka Cannibal! The Musical). Parker has also noted Troma as inspiration for his style of filmmaking and for South Park (1997).
Trey Parker and Matt Stone had originally intended for the film to be a musical; like their previous film, Cannibal! The Musical (1993) (aka Cannibal! The Musical). Unfortunately, they had trouble enough finding investors for the unusual story of Orgazmo on its own, so that idea was dropped.
The clips from the movie that are seen playing in the video store were taken from a fake trailer for the film, made by the filmmakers before production ever started, which was shown to potential financial backers to try to raise money to make the film. (This is discussed in the "drunken commentary" feature on the DVD)