Grind Boots

Ever try grinding a rail on a skateboard? It is as hard as it looks. But not as hard as grinding one without a board. Despite this a surprising number of characters are able to do just that. Sometimes they don't even need a rail, they can grind just as well down any slope.

Extra style points for shooting at the same time.

Named after the equipment from Ratchet and Clank that allows the main character to grind rails.

Anime and Manga

 * Full Metal Panic does this in the episode "The Rising Wind In The Homeland, Part 2", with Humongous Mecha discharging oversized shotguns while sliding freely down a steep hill.
 * An episode of Inuyasha features InuYasha and Miroku rushing to the aid of the populace by sliding down a grassy hill.
 * Lady Alvida of One Piece can now do this, thanks to her Devil Fruit powers.

Film

 * Chev Chelios in Crank 2: High Voltage attempted this, but failed while crushing his balls.
 * In Daredevil, a young Matt Murdock does this after mastering getting around while blind.

Video Games

 * As noted above, Ratchet and Clank
 * Sonic the Hedgehog series.
 * Soap shoes were featured in Sonic Adventure 2 in order to introduce rail sliding to the series. Although the games no longer feature the brand, the rail grinding has remained. Originally only Sonic and Shadow could grind. Now anyone can grind, even those without shoes, like Omega and Big. In other words, in the world of Sonic, people really really like Soap shoes.
 * Sonic Heroes feature grinding as part of the gameplay. It's pretty noticable how the rails magnetically attracts any characters who have their shoes close to the rails. Miss, and oblivion awaits.
 * In Sonic the Hedgehog (2006), the Kingdom Valley level features special poles with a bar on a green orb on the end. Hitting these orbs causes them to spin around the pole and create a small pathway made out of spiralling wind that one can grind on.
 * A level in Gunstar Heroes has the player(s) sliding at high speed down a hill, fighting off sliding bad guys all the while.
 * In the video game Psychonauts, the main character, Raz, can grind on anything -- branches, ropes, wires, monorail tracks, wooden rails, tables, and probably your nose. It's handwaved by him being raised in a circus.
 * Once Raz starts his grind, he won't stop until he reaches the end of whatever he's grinding on, or he jumps off. You can literally be going at a snail's pace and the game will still play the grinding noise and have splinters of wood fly out from behind his shoes.
 * In Final Fantasy X, most of the party dramatically grinds down the mooring-cables of your Global Airship to rescue Yuna from being forcibly married to a villain. The clip follows the path of The Hero, Tidus, and focuses on the sparks flying off of his shoes and his coordination to jump between the crossing ropes in midair. What it doesn't focus on is Kimahri doing the same thing while barefoot/pawed and carrying Lulu, the next tallest party member.
 * Yuna can do her own on a chain under Bevelle in Final Fantasy X 2. Presumably her party members do too, but we don't see them.
 * Characters in Jet Set Radio employ grind boots capable of grinding anything even if it goes directly up.
 * Sly Cooper learns the Rail Slide technique after Episode 2 of the first game.
 * Blood Rayne can do it on most railing, but it's probably just a standard Lesbian-Nazi-Hunting-Ninja-Vampire power in that world. In an evening gown, without mussing her hair. Can't top that.
 * The eponymous Ty the Tasmanian Tiger can grind on rails and ropes. Bare pawed.
 * This is a crucial ability in the Tribes series. In the first game, it was simply a glitch that allowed you to grind at superspeeds down any slope steep enough. In the second game, they refined it to be accessible to players with less practice, and in the third it was such an official feature that it has its own appearance and animation, and can be done on horizontal surfaces. It's called skiing, though.
 * Nearly all of Dissidia Final Fantasy's stages all have "grind bars" of some sort. What they look like depends on what stage you're on, the can be arcs of light, walls, stone ridges, or the freaking Lifestream itself!.
 * In Scaler, Scaler can grind bare-clawed on rails. However, grinding plays a bit of an important role, as it is the only way for Scaler to charge up energy, which can then be used in an electric attack.
 * When Sora visits Tarzan's world in the first Kingdom Hearts, there's a minigame where the two of them go tree-surfing. To make this even weirder, if you make the right turns you end up sliding through a cave.
 * In John Woo's Stranglehold Detective Tequila is able to grind down rails while shooting enemies in slow motion.
 * In In Famous, Cole can grind on any electrically charged surface, including power lines and electric train rails.

Web Comics

 * Used in Darken during The Race.
 * Featured as part of the Agility Trials in Last Res 0 rt, when Daisy tries to grind using her Artificial Leg. It doesn't end well.

Western Animation

 * Cyborg from the Teen Titans also demonstrates this ability in the episode "A Date With Destiny". Sliding down the cables of a bridge while shooting his Arm Cannon -- Booya!
 * The Disney Tarzan movie, and the George of the Jungle movies.
 * Batman, Nightwing and the Red Hood all do this in a chase scene in Batman Under the Red Hood.

Truth in Television

 * Real life example: Soap Shoes are shoes with a built in plastic concavity in the sole to allow grinding rails.
 * Some sneakers have insoles made of hard plastic. This invocation is usually one-footed and unintentional.