The smiley, smiley face, or happy face, is a stylized representation of a smiling human face, commonly represented as a yellow button with two dots representing eyes and a half circle representing the mouth. "Smiley" is also sometimes used as a generic term for any emoticon.

Origin
The graphic was popularized in the early 1970s by a pair of brothers, Murray and Bernard Spain, who seized upon it in a campaign to sell novelty items. The two produced buttons as well as coffee mugs, t-shirts, bumper stickers and many other items emblazoned with the symbol and the phrase "Have a happy day" (devised by Murray Spain).
The smiley was one of the many icons adopted by the acid house dance music culture that emerged in the late 1980s, as engraving famous logos on ecstasy tablets was a common practice at the time.

Popularization
The smiley has become an essential of Internet culture, with animated GIF and other image representations, as well as the ubiquitous text-based emoticon, " :) ". The smiley has been used for the printable version of characters 1 and 2 (one "black", the other "white") on the default font on the IBM PC and successor compatible machines, though modern fonts for graphical user interfaces often do not include those characters.
The Wingdings font also includes a smiley:
Smileys and emoticons are often used on Internet forums. Although smileys are only intended as an extra feature, some users often reply to threads with a single smiley, which often considered to be spam on many forums. However, the use of smileys, can sometimes distinguish a message between a flame and a joke. For example, "You're a bit slow, aren't you? :)" is less likely to be interpreted as an insult than without the smiley.

Internet use

Main article: Emoticon Smileys using computer keys
In May 2002, Luke Helder, a midwestern pipe-bomber, tried to replicate a smiley face in his pattern of pipe bombs. His first 16 bombs formed circles, the first in Nebraska and the second on the border between Illinois and Iowa. Those bombs completed the eyes. Two other bombs in Texas and Colorado were apparently the beginnings of the smile. However, he was captured before being able to complete it.
A certain species of Hawaiian spider, Theridion grallator, a.k.a. the Happyface Spider, has some morphs which display an uncanny smiley-face pattern on its yellow body.
The smallest incarnation of the smiley was created by Paul Rothemund of the California Institute of Technology. He used strands of DNA in a method he calls DNA origami to construct a complex two-dimensional nanostructure in the shape of a smiley face.
The 230km (143 mile) wide Martian crater Galle (on the Argyre Planitia) very strongly resembles a smiley face.
A smiley face can be seen within a properly placed dental implant in a dental radiograph.

Smileys in popular culture

ASDA & Wal-Mart use the smiley in their "Rolling Back Prices" campaign. In 2006 Wal-Mart sought to trademark the smiley face in the US, coming into legal conflict with Franklin Loufrani and SmileyWorld over the matter.
In 1986, Eat'n Park first introduced the "Smiley" cookie.
The "Sonar" Music Festival is actively using the "Smiley" logo in its campaigns. Advertising

The yellow smiley is a recurring theme in the comic book series Watchmen (Alan Moore & David Gibbons, 1986). The smiley is used as an insignia by the character named "The Comedian." An image of a smiley face with a streak of red (originally blood) across it both begins and closes the series, and appears on the cover of the graphic novel reprint.
In Wolverine, the minor shape-changing villain Dirt Nap is recognizable by his smiley face symbol, which is retained between forms.
In the comic book series Transmetropolitan the smiley with three eyes logo features as the symbol of the Transient Movement, a group of humans in the process of morphing their DNA with that of aliens, and was later used as a symbol of the series itself. The 2001 movie Evolution used a similar smiley in promotions a number of years later under license from Smileyworld Ltd.
In the comic book series The Tick, the Chainsaw Vigilante wears a yellow smiley face button on the lapel of his leather jacket, oriented upside-down in an apparent expression of irony. His mask is also a significantly stylized version of the smiley and the classical comedy/tragedy masks.
The Chaos! Comics character Evil Ernie has a sidekick called Smiley the Psychotic Button, a sentient smiley button with a sinister face and backed by crossbones.
In the 2003 comic Solus a fragment of Danik is named Polla and looks like a talking smiley.
The popular graffiti artist Banksy has used smileys in several of his works, including one that shows a man in full riot-police gear with a Smiley for a head.
The Banksy riot-police version of the Smiley was used in the graphic novel The Smoke.
Stephen King's reoccurring villain Randall Flagg often wears a smiley badge.
Gahan Wilson has drawn several cartoons with smiley faces: among them, one shows a group of cops wearing smiley-face masks in an interrogation to break down the resistance of the person being interrogated.
The DC comic four-issue mini-series Prez featured a shady political boss named Mr. Smiley. This short series was referenced in Issue #54 of Neil Gaiman's seminal comic book series The Sandman. In the Sandman story, "Boss Smiley" controlled all of Prez Rickard's reality.
In the webcomic Misfile, Rumisiel wears a T shirt with a non-smiling smiley and the caption "Have a day" Art and literature

The film Forrest Gump (Robert Zemeckis, 1994) comically featured the smiley being "invented" when the main character wipes his mud-covered face off with a yellow t-shirt, and says "Have a nice day", inspiring a struggling businessman with the makeshift design. This scene is not in the original book.
The film Fight Club (David Fincher, 1999) has a brief "smiley bombing" scene on the side of an office building. A similar face previously appeared in the Fight Club novel.
In Timescape, an episode of Star Trek: The Next Generation, Captain Jean-Luc Picard drew a smiley face in the cloud created by a warp core breach in progress that was frozen in time and laughed hysterically for a moment before becoming extremely panicked, all as a result of "temporal narcosis".
In the 1995 film Virtuosity a smiley is used to mark a restaurant where the virtual serial killer "Sid 6.7" was hiding.
In the 2001 film Evolution a three eyed Smiley is used as a symbol for aliens.
A smiley can be vaguely seen on the bloodstained medical gurney in the crash scene of Fear and Loathing in Las Vegas.
In Lost, one character landed on the island in a balloon with a smiley face on it.
WWE wrestler Mick Foley's most common logo is a smiley with his trademark Mankind mask over it. Also in his Mankind persona his catchphrase was "Have a nice day!", used ironically as a sinister heel and more literally as a comic face.
On Google Video, there is a video series called "Smiley Face...™" with a Smiley Face created in paint and singing to different songs created by Kent Dodds Productions.
In the 2007 film Smiley Face. Movies and television

The band Nirvana used a smiley face that was altered to appear drunk or high as their logo, a good reason for this is both one of the claimants to the creation of Smileys being from Seattle – an area key to the 1990s' grunge scene – and the increasing popularity of smileys throughout the 1990s.
The band Blink-182 also used an altered smiley face with arrows(similar to Nirvana's)for the cover of their self-titled album in 2003. Software

Smiley Xtra, a Mozilla Firefox extension.
Emoticon
Kaoani
ASCII art (text/ASCII smileys)