The Magic Touch

Sometimes, one touch can change everything.

Literally touching one or more mundane objects (weapons, sticks, rocks, etc.) to transform them into awesome objects by infusing them with magic.

To repeat, it's just as easy as touch and go. You can, for example, make your pointy stick vibrate for extra killing potential or make your Blade on a Stick acidic. The important thing is that it is possible without a long amount of time or outside influence, such as The Blacksmith or, in extreme cases, tools.

You may also ask how is this different from Magic-Powered Pseudoscience? For the most part, the characters pulling this stunt know what they are doing and are under no illusion of "Pseudo"-science.

See also: Elemental Punch and Spell Blade.

Examples of The Magic Touch include:

Anime and Manga

Magical Girl Lyrical Nanoha: Cinque's Inherent Skill "Rumble Detonator" in StrikerS turns any metallic substance she touches into high-grade explosive. Combined with her other special ability to summon any number of steel throwing knives, it turns her into one of the most dangerous girls around.
- See Gambit, below.
Slayers has Astral Vine to enchant anything sharp including corporeal spell effects to damage targets immune to normal weapons.
Omamori Himari has the Light Ferry ability of the Amakawa family.
In Puella Magi Madoka Magica, this ability is possessed by Homura (along with a Shield of Holding), in contrast to most Puella Magi who summon magic weapons. Given the loose nature of magic in the setting, theoretically all Puella Magi could have this power.
- And they do - Mami was able to transform Sayaka's metal bat in order to help her fight (not being a Puella Magi at that point), and Kyouko transformed a pair of binoculars to theoretically make them see further.

Comic Books

Gambit of the X-Men has the ability to turn anything he touches into an explosive. Although he prefers to charge and flick playing cards at his opponent.
The Silver Samurai of Marvel Comics, after his reveal as a Mutant with Absurdly Sharp Blade as his power.
Another Marvel Universe character, Harpoon, could charge a metal spear with his own bio energy and use it as a devastating weapon.

Film

Ghost Rider: Johnny's motorcycle and a random shotgun.
Cinderella: The pumpkin ~~king~~ coach and partially the nifty dress.

Literature

In The Chocolate Touch a boy has the same gift as Midas but with chocolate instead of gold.
Michael in the Knight and Rogue Series develops the ability to 'enhance' the properties of things, making water more effective while fighting fire, giving his horse Super Speed, and on one occaison making the air thicker to break his fall.
Berserker, the resident Hero-Killer of Fate/Zero, has a combination of this power, Instant Expert, Implausible Fencing Powers and Super Strength, with the result that he can rip a telephone pole out of the ground and use it to completely overwhelm a legendary swordsman with an Infinity+1 Sword. Oh, and any magic weapon he holds responds to him as if he were its master. One of the biggest Oh Crap moments in the story comes when he manages to get his hands on a jet fighter.

Mythology

Midas thought this was a good idea, he learned.

Tabletop RPG

Dungeons & Dragons: Gauntlets of Ghost-Fighting for when you want to kill incorporeal things but don't want to enchant all of your stuff. Even older are Gauntlets of Weaponry Arcane that make any weapon held count for purpose of immunities as silver and +1 to what it normally is.
- Or for a less flavorful version you could learn the magic weapon/fang spell and hope the enchantment lasted long enough.
A Feat sorcerers can pick up in the tabletop game Pathfinder lets you make your normal weapon into a magic plus 1 weapon by channeling magic into it.
Werewolf: The Forsaken has the rite of ~~dedication~~ pants. Interestingly enough, most Klaives don't count since they require the outside influence of a spirit and a great deal of time/effort.
In Changeling: The Lost, a lot of Clauses seem to work by empowering a prop, this is most clear in the case of the Entitlements: College of Worms, The Scarecrow Ministry, Bodhisattvas of the Broken Cage, and Squires of the Broken Bouch.
In Mage: The Ascension, Mages can imbue objects with energy, thus for example allowing them to hit ghosts.
Warhammer 40,000: The first few stages of the obliterator virus work like this, up until you can't remove your weapons or armor anymore.

Video Games

In Eternal Darkness, you learn the "Enchant Item" spell quite early on. While it can be used to power up weapons, it's also used to repair broken (by plot events only) items and at one point near the end make a C4 bomb powerful enough to destroy some catacombs full of Eldritch Abominations.
In The Elder Scrolls Oblivion, poisons work this way. If you make a potion with only negative effects you can apply it to your weapon. While you're technically just using Poisoned Weapons, the poison is alchemical in nature, has most of the same effects as magic and allows the poisoned strikes to affect incorporeal creatures (magical weapon) regardless of type.
In the Makin' Magic expansion pack of The Sims, any Sim with magical powers can use the Enchant spell to temporarily bring a garden gnome or lawn flamingo to life — or even just make the fridge open and close by itself as it pleases, or make the checkers on the checkerboard dance around.
In the Devil May Cry series, Dante can shoot enchanted bullets, shotgun blasts and grenades when using his Devil Trigger. It's impicitly his touch that makes this possible.
- Similarly, in Devil May Cry 4, Nero charges his shots by holding the gun with his demonic arm.

Web Comics

The Non-Adventures of Wonderella: On this page, Wonderella gains the power to give life to anything she touches.

Western Animation

Avatar: The Last Airbender: Apparently, Zuko can light up his dao swords.
In The Smurfs episode "Smurfette's Sweet Tooth", Smurfette gained the power of turning whatever she touched into smurfberry candy.