Tesla's Anything Copier (The Prestige)
In the surprisingly awesome non-Batman Nolan movie, The Prestige, David Bowie invents a teleportation machine for Wolverine because he thinks Batman killed his wife. In a shocking twist, it turns out the Teslaporter works sort of like a fax machine: It doesn't send the user from one place to another, but rather makes copies of him. The bonus here is that you have no way of telling who the original is.
Gollum, Bowie and Wolverine demonstrate what a good idea looks like visually.
Jackman's idea was quite simple. Use the machine to perform a magic trick, and sell tickets to make a nice living. Of course the Jackman copies had to be killed by rigging a water tank under the receiving end of the machine so that a clone would appear into the world, presumably with all of the original's memories, and immediately die a horrifying, drowning death.
His plan was to repeat this existential nightmare a couple dozen times in hopes of luring Christian Bale backstage, frame him for murder and possibly molest his daughter in the future.
"Hocus pocus? More like Hocus poke-her! And by her I mean Christian Bale's daughter. And by poke, I mean euphemist-"
"Just shut up."
What It Should Have Been Used For:
Hey, how about putting a slab of gold in that machine and becoming an instant billionaire? Yes, it can clone inanimate objects--the first thing we see it copy is hats. Then he could bribe the right people and wham, Bale will be having his bat-anus stretched in prison before dinner.
Good lord, this is the early 1900s we're talking about. In those days, magicians were below dung collecting pedophiles in the social hierarchy. There just had to be better uses for the teleporter besides (possibly) committing clone homo/suicide on stage every night and leaving huge vats of floating evidence behind.