Easter egg: On the DVD, if you use the Infinite Improbability Drive, you have a chance to see the cartoon that Deep Thought watches. There is no way to access it via menus.
Visible crew/equipment: When Ford runs past the caravan to chase the Vogons with a towel, you can see the cameraman, and about 4 other crew members reflecting in the caravan's surface.
Slartibartfast: You must come with me, quickly or, or you'll be late!
Arthur: Late for what?
Slartibartfast: What? Oh, no...What is your name, earthman?
Arthur: Dent. Arthur Dent.
Slartibartfast: Late, as in the late Dentarthurdent. It's a kind of threat, you see.
Trivia: At the very end of the film, when the group uses the Improbability Drive to go to the Restaurant at the End of the Universe, there are a lot of images that flash onto the screen when the drive is activated, so in the other parts of the film. In this case, the very last image shown is the face of Douglas Adams, the creator of the Hitchhiker series.
Question: Anyone who's read 'Life, The Universe & Everything' will now why the bowl of petunias thought 'Oh no, not again' just before it plummeted towards Magrathea, but had Douglas Adams already conceived that backstory and just couldn't fit it in to the narrative at the time or was it something he only came up with when writing part 3?
Chosen answer: Because it was a radio show originally, Douglas Adams would write broadcasts from show to show. He did not know where something would lead, which let the plot become random and funny. So ultimately it was originally created to be funny, then he found a way to link it back in later.