Angels Pose

The originators of this very trope.

When a team, generally young women, pose in a distinctive style in the midst of battle. It looks pretty good on camera and it conveys teamwork. The general appearance is usually dependent on a symmetrical three person shape, the two on the outside have their body positions turned away from the center person. A silhouette is optional. But there is also a two-person variation of them standing back to back. Often done in a Montages.

No actual firearms are (usually) involved though.

Originated by the famous poses of Charlie's Angels

It is often used as a Stock Parody. Compare the Super Sentai Stance.

Examples of Angels Pose include:

Anime and Manga

At the end of most opening sequences of Gantz, Kurono, Masaru and Kishimoto strike the Angels Pose.
This was the usual eyecatch of the anime series Miami Guns.
Naturally, in Dirty Pair, the Lovely Angels do this too.
One of the Title Sequences for Bleach has this, featuring Rukia, Orihime, and Rangiku. Actually played perfectly straight, without a hint of parody or humor.
This apparently official Gainax piece of art, for Neon Genesis Evangelion.
Moka, Kokoa, and Rubi do it in Rosario + Vampire.
Those Three Girls from Hayate the Combat Butler do one when explaining to Hayate that they're the class officers.

Films -- Live-Action

Parodied in Wrongfully Accused when a trio of FBI agents enter a room. Only one was female.
The Girls from Thunder Strip poster. Probably the only version with a gaff hook.
Humorously parodied in Scary Movie 2.

Live-Action TV

Happens during any game of Film, TV, and Theater Styles where Charlie's Angels is one of the styles.
It was done in at least one episode of That '70s Show which of course actually had Tanya Roberts who was one of the Angels on it.
The title sequence for Funky Squad, an Affectionate Parody of 70's cop shows.
In the Flight of the Conchords second-season episode "Prime Minister", the Prime Minister of New Zealand wants a photo like this. With a Barack Obama impersonator (who he thought was actually Obama).
Done unintentionally in Whose Line Is It Anyway? when Robin Williams was a guest.
The late 70s Hardy Boys TV show's third season opening featured a silhouette of Frank & Joe in action.

Music

Destiny's Child did this a lot when performing their smash hit "Independent Woman (Part I)" (don't ask about "Part II", just don't). Makes sense, considering that it was for the Charlie's Angels soundtrack.

New Media

Most any picture on the internet featuring multiple (non-model) girls with guns. Though, these usually feature all the chicks in the picture brandishing some sort of firearm.
Or, for that matter, just about any picture of two or three women under the age of thirty on any social network; guns are generally faked with their hands.

Tabletop Games

Spelljammer boxed set cover. With a mindflayer.

Video Games

Final Fantasy
- Yuna, Rikku, and Paine from Final Fantasy X-2 like to do this a lot.
- In Final Fantasy XIII, the entire party will strike a pose any time they do a Paradigm Shift, even if it means opening themselves to attack.
The standard pose for Commander Shepard's squad when bursting through a door in Mass Effect 2. Though it is entirely possible that the squad can consist of young men, or can be of mixed genders, or can include a nine-hundred year old woman who looks like a young woman.
Used by Max the Robot Dog, Dr. Hawkins, and Kurt Hectic in the video game MDK2, specifically on the cover of the manual. MDK2 also has a version that must be seen to be believed. You can find it in page 5 of the manual
A Mildly disturbing version in Ratchet and Clank, with a trio of Blarg commandos.
Dante, Trish, and Lady do this in Devil May Cry 4.
Even Pokémon Mystery Dungeon has to get in on the fun.^{[dead link]}

Web Comics

Used in this strip of The Order of the Stick. Note that only Haley (right, with the bow) is the only one of the three who is really a woman—Roy (center) was temporarily female at the time due to a Girdle of Femininity/Masculinity, and Vaarsuvius's gender is unclear at best.
"Charlie's Archons" in Erfworld strike variations on the Angels Pose when they first appear and when they first show their combat abilities.
Pose as a team, because SHIT JUST GOT REAL
The KAMics with this picture.
M.Organ Art (NSFW) did it with the D.U.S.T. Bunnies.
Rusty and Co. does it with its trio of Monster Adventurers.
Platypus Comix once had a banner with Mulberry Sharona, Shroomy, and Princess Pi striking this pose.
Not in the comic itself, but rather the bonus "Volume 9 Special Wallpaper" for Girl Genius has Gil, Agatha, and Tarvek in the Angels Pose.

Western Animation

Done in X-Men: Evolution in the Bayville Sirens episode, though it's hard to catch as it only appears on a television screen for a few moments.
The title logo of Codename: Kids Next Door, a clear parody of the Charlie's Angels one. Its intro animation actually shows them jumping into the logo one by one.
- This logo was then parodied in the book Fat Camp Commandos.
Done at one point in the original opening theme of Totally Spies!
The animated kids' show Mickey Mouse Clubhouse does this for a brief moment in a spy-themed episode with Minnie, Daisy, and uh... Mickey.
Parodied by The Ember Island Players in Avatar: The Last Airbender, as an homage to the fan term Ozai's Angels.
Dexter's Laboratory gave us G.I.R.L. Squad, with an opening montage ending in one of these.
Space Ghost Coast to Coast used the pose in their episode parodying detective series of the 1970s. Animator C. Martin Croker said he drew Zorak's silhouette to look as though he was explaining directions to someone rather than preparing a karate chop.
The opening title sequence of Beavis And Butthead Do America parodies this and every other 70's cop show. Butt-Head states in an interview that it's because the 70's are the last time Mike Judge got laid.
The 90's chapters of Secret Squirrel used it on the opening credits of one episode.
In the Phineas and Ferb episode "Phineas-and-Ferb Busters!", Candace does this with her friends Jenny and Stacy after putting them through a Training Montage.