Palm Fist Tap

caption-width-right:300: *BOP!*

Sometimes when a character has an Idea Bulb moment, he may reflect it by holding one hand (usually the left) out and tapping the palm with the other fist. You've probably Seen It a Million Times.

Often the action is accompanied by a sound effect: a "bop" or a "bing". The Japanese onomatopoeia for the drum is oberobero. Anime producers often use the sound of a tsuzumi drum hit.

Compare Idea Bulb and Beam of Enlightenment.

Anime and Manga

 * Here is an example from Baka to Test to Shoukanjuu, the sound effect having been translated "bam". And apparently the onomatopoeia for the drum is oberobero.
 * The Magical Girl Lyrical Nanoha The Movie 1st Tribute Comics which doubled as advertisements for the four Nanoha manga running at the time of the movie release has Subaru doing this in the Lyrical Almanac section when she was pitching ideas for the StrikerS movie. ("Erio and Caro's Meeting - The First Touch!")
 * Seen every now and then in Historys Strongest Disciple Kenichi. As shown in the picture, Akisame-sensei takes Kenichi's request for a day off and figures that it's been a while since anyone else has had a vacation anyway.
 * Haruhi in the first episode of Ouran High School Host Club when she comes up with a word to describe Tamaki. "I got it...Obnoxious!"
 * Naruto occasionally.
 * Tomoki does this in one episode of Heavens Lost Property. The accompanying sound effect dragged on for a few drum beats instead of just one.

Live Action Television

 * Robin from the 1960s Batman series did this quite often, usually accompanied by a "Holy ____, Batman!" exclamation.
 * This was a common gesture for Sabrina in Sabrina the Teenage Witch.
 * Eddie from The Cosby Show also did it.
 * Both Will and his cousin did it in Fresh Prince of Bel Air

Film

 * Ron did this in Harry Potter.

Video Games

 * Jack Skellington does this quite a lot in Kingdom Hearts: 358/2 Days, thanks to the game's heavy use of Going Through the Motions with character animations.
 * Mike Meekins does this in Phoenix Wright: Ace Attorney, then yanks on his hand since he did it with his bandaged hand and he hurt himself doing it.

Real Life

 * Western politicians sometimes do this to drive a point home during their debates. (It's questionable whether they're actually realizing something when they do it — more likely they want to signal to the audience that they should be realizing something because of what the politician just told them.)