Finger Framing

Using the index finger and thumb of both of your hands to make a rectangle and looking through it. Most likely used by photographers or movie producers.

Examples of Finger Framing include:

Anime and Manga

Eshi in D.Gray-man has doing this constantly as one of his character quirks.
May from Pokémon does this when she pretends to be on some kind of documented adventure.
In RahXephon, Ayato often does it towards subjects he plans to paint.
Done in Zan Sayonara, Zetsubou-sensei by Chiri when adjusting a painting.
In the Finder Series, Akihito does it in the island since he did not have his camera.

Film

Genie does this in Aladdin. "You've just won the heart of the Princess! What are you gonna do next?"
- Then does it again in Aladdin and the King of Thieves. "Oh, it's a Kodak moment!"
Variant in Rango: the titular lizard exhales on glass before drawing a screen with his finger. The Spirit of the West does the same thing while he's giving Rango the will to continue.

Literature

Silverfish does this to Victor in the Discworld novel Moving Pictures, when deciding he'd make a great moving picture star. Since Silverfish has only just invented the clicks, Victor has no idea what he's doing or talking about.

Live-Action TV

The Brady Bunch was cast as the "Average American Family" in a commercial for Best detergent. The hippie director who directed the commercial did this.
One of the candidates on the 2009 UK season of The Apprentice infamously did this constantly on the advertising task. it made him look like a pretentious idiot, as this often does.
A character in one Cracker story did this a lot; he was somewhat autistic and fixated on movies. Someone else commented on it at a funeral that included the quote "We see the world through a glass, darkly": "You don't see the the world through a glass, darkly. You see it through your fingers."
Midsomer Murders: One of the characters says "I've been framed" while making a similar gesture in "The Killing at Badger's Drift".

Video Games

The world of Amazing Island is set inside a giant storybook, so doing this actually allows you to take photographs. Well, they're called Fotos, but they're still pictures captured on your heart by the special bond between you and your monster.
This is an idle animation in The Sims 2 and 3, for Sims who are involved in the Arts & Crafts hobby or have the Artistic trait, respectively.
Now available as a taunt in Team Fortress 2 called "The Director's Vision".

Web Comics

Homestuck: When Jade Harley is enlarging the Fenestrated Wall to enable her and John to ride a battleship through it, she does a slowly enlarging finger-frame matching its borders.

Western Animation

Goofy does it in How to Hook Up Your Home Theater while figuring out where to put his new TV set.
Used in the American Dad episode "Stan's Night Out" in the B Story, in which Roger tries to be a beauty queen. He discovers that his date is taking him to a Pig Party. He then does this to the other girls at the party...and then looks at mirror, framing himself in it, and discovers that he is the Tomato in the Mirror (ugly, not evil).
A zombie director in the Courage the Cowardly Dog episode "Everyone Wants To Direct" does it. Then his hand falls off.
Pinkie Pie does this (with hooves, somehow) while setting up a prank in the My Little Pony Friendship Is Magic episode "Griffon the Brush-Off".
Eddie Storkowitz of Birdz does this a lot.

Real Life

There's a wearable-computing technology called SixthSense being developed^[when?] at MIT that's controlled by hand gestures — one of which is the finger-frame gesture, which means "Take a photo of whatever's in front of me".