A little light invention retrospective for a Monday morning, courtesy of Gizmodo: a photo gallery of Thomas Edison’s strangest inventions.
Here’s one example to pique your curiosity, the electric pen:
It begs the inevitable question: “Why?” When did a non-electric pen strike Edison as an exercise in unnecessary frustration?
Apparently, it sort of became the forerunner of the electric tattoo machine, so now we have Thomas Edison to blame for idiot celebrities spelling their names wrong in Sanskrit in a permanent disfiguration of their torsos.
Engineering & Technology magazine 
Time Magazine has an article that states this invention was the forrunner to the mineograph machine; it could make multiple copies.
Nice addition – thanks.