The Point of View gun is a weapon that appears in the 2005 movie but not in any of the prior versions of the story. The gun was designed by Deep Thought. It makes the victim see things from the shooter's point of view. page 
YOUTUBE ndmykHs_TK8 Hitchhiker's Guide to the Galaxy - The Point of View-gun
I was not familiar with this element of the story as I believe it was developed by the film's writers and producers to give Trillian (played by Zooey Deschanel) a more active role in the story. Will need to ask Robbie about that?
My interest in it here is with regard to perspective, which is a recurrent theme in my thoning and what draws me to work with Hitchhikers.
Point Of View Gun - from The Hitchhikers Guide to the Galaxy
> The Point of View gun conveniently does precisely what its name suggests. That is if you point it at someone and pull the trigger, they instantly see things from your point of view.
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> It was designed by Deep Thought, but commissioned by a consortium of intergalactic angry housewives, who after countless arguments with their husbands were sick to the teeth of ending those arguments with the phrase "You just don't get it, do you?" - clip.cafe
YOUTUBE YsgbcYnmR6Y Hitchhiker's Guide to the Galaxy - The Point of View-gun
In the film: The gun is given to the characters by a group of female beings called the Intergalactic Consortium of Angry Women. When fired, it causes the target to feel exactly what the shooter is feeling—instantly and overwhelmingly. This is used humorously and thematically to explore empathy and misunderstanding between characters.