A banana peel is the skin of a banana once the fruit has been removed; prior to this, it is skin. It is traditionally used in film, television and video games as a lethal weapon.
A staple in comedy, along with its older brother, 'cream pie in the face', the banana peel slip probably originated during the silent film era, when people's standards and expectations were perplexingly low.
There are rumors that Charlie Chaplin discovered the gag one lunch-break on the set of 'Modern Times' while, ironically, eating an apple. Supposedly, Chaplin threw his scraps on the ground in a fit of rage caused by a stubborn producer who insisted on changing the title of the film to 'Humorous Contemporary Difficulties'. After a heated exchange, the producer stormed out and accidently slipped on Chaplin's apple scraps. This caused Chaplin and the entire room of cast and crew to burst into a fit of laughter; the paramedics joined in too, while they wheeled the producer to the morgue. Chaplin would later change the apple scraps to a banana peel because a banana peel is more recognizable on screen.
Of course, this is merely hear say and quite possibly utter bullshit. The actual origin is far more likely to be something closer to this.
Nowadays, we see the banana peel slip express itself in many different forms:
In the movie Billy Madison, Chris Farley's character, known only as 'Bus Driver', throws his banana peel out the window of his bus. Later, the rotted, and therefore extra-slippery banana peel causes the O'Doyle family's car to uncontrollably plummet off a cliff. We can only assume that all passengers were killed.
Wanted for manslaughter.
Originally on Mario Kart for SNES, and again in every subsequent addition to the series, the banana peel is a great source of great frustration for avid karters. Especially when you are coming first and a slip moments before the finish line allows 5 players to pass you while you scream "bullshit!", swear the game is somehow screwing you, and vow to never play with cheaters again; or, when you are coming last and you keenly attempt to pick up a '?' box expecting an item adversly proportionate to how much you suck but instead slip on about a dozen banana peels cleverly set by less sucky players.
"Don't worry, John, you can still come back; there're some boxes coming up..."
In just about every cartoon ever made, someone or something has slipped on a banana peel. So axiomatic is this that there is a corresponding sound effect which you'll find filed in the 'childhood' section of your brain.
A woman sued a shop owner after she was severely owned by a banana peel. Unfortunately for her, the defendant was the owner of a 99 cent store and, presumably, had spent all his money on sharpies for blacking out the expiration date on cheese.
The MythBusters team tested whether or not a banana peel would always cause a person to slip. Although they deemed this extremity busted, we still got to see Adam slip on his arse; and that's pretty freakin' funny. If they'd been testing whether people slipping on banana peels was funny, the myth could quite certainly be deemed plausable.
Is there a place in the future of comedy for the humble banana peel slip? Well, if fart and dick jokes have taught us anything it's that immaturity is a comedic certainty that crosses cultural borders and age groups, undiminished by the passage of time. Along with fart and dick jokes, people getting hurt is the final side of the Triangle of Imaturity. So, although the classic banana peel gag may no longer be ripe, its essence will live on forever. Hell, Funniest Home Videos, its spiritual offspring, has proved this for many years; sound effects and all.
Nature's most solid structure.