The Fifth Element's Jean-Baptiste Emmanuel Zorg is not a nice man, but he sure knows how to design one hell of a sci-fi gun. His ZF-1 rifle — which is a machine gun, flamethrower, rocket launcher and so much more — has inspired its own following of admirers, including Adam Savage of the MythBusters.
There are a few replicas of the ZF-1 floating, and even some that you can buy. That said, they're expensive, and the ZF-1 that appeared in the movie was actually several different prop guns — including some that were specially made to show off one feature or another, such as the aforementioned flamethrower or an arrow launcher (with exploding or poisonous gas tips, of course).
Before we go any further, I feel I should let Zorg run through the rest of the ZF-1's capabilities because he does such a good job:
Half the fun for someone looking to build their own ZF-1 is choosing which functionality to go with, as we don't yet have the technology to pack all of those capabilities into a rifle of that size. So, do you go net launcher? Do you try to replicate the "ice cube system" that freezes targets until their brittle and about to break? Prop gun makers can even make a ZF-1 with the Replay functionality. It won't fire, of course, but, in the movie, a Replay sensor deploys when the gun is in that mode, and enthusiasts can recreate that.
In the video below Adam Savage talks about his ZF-1 obsession with Tested's Norman Chan. By his own account, he's been working on the gun for 13 years and its his oldest standing project that hasn't been completed. It sounds like a serious labor of love, one that has been a collaboration between Savage and the prop-making community.