Tourist guy
The "tourist guy"  was a hoax that featured a digitally altered photograph of a tourist on the observation deck of the World Trade Center, supposedly on the day of the  September 11 attacks, showing a plane about to hit the  tower in the background. The photo became an Internet phenomenon as many manipulated pictures spread online. The man in the photograph was identified as Hungarian Péter Guzli, who took the photo in 1997. Guzli said he edited the photo as a joke for his friends and did not realize it would spread across the Internet.

He is also called numerous other names, including the "accidental tourist" (a reference to the novel and film The Accidental Tourist), "Waldo" (a reference to Where's Waldo?), the "WTC Guy", and the "tourist of death".

Origin
Shortly after 9/11, an image surfaced on the internet, purportedly from a camera found in the debris of the World Trade Center. The image showed a man, dressed in a wool cap, heavy jacket, and backpack, standing on the observation deck of the World Trade Center. Below him, a jet plane can be seen flying towards the building.  Because of its closeness and low altitude, it seems certain to collide with the tower. The picture purported to be one taken mere moments before the attacks on the World Trade Center began.

Inconsistencies
Hoaxapedia from Museum of Hoaxes' online encyclopedia listed some of the inconsistencies that ultimately confirmed that the photograph was a hoax. These include:

 It stretched credulity to believe that a camera could have survived such a fall and not smash into pieces upon hitting the ground.
 The temperature was  the morning of the attacks, yet the man in the photo was wearing heavy clothing consistent with winter weather.
 The man would have been standing on the South Tower, which had an observation deck; yet the North Tower, without such a deck, was the first to be hit. It is unlikely anyone would be posing for an image after the North Tower was hit.
 United Airlines Flight 175 crashed into the South Tower from the south. However, it is evident from the fact that Midtown Manhattan is in the background behind the man that the plane in this photo is approaching from the north, consistent with American Airlines Flight 11. The plane in the picture clearly displays the American Airlines livery on its nose.
 Both planes that were flown into the towers were Boeing 767s, whereas a Boeing 757 is shown in this photo.
 The plane likely would have been blurred in the photo due to its high velocity before impact.
 The photographer is not likely to continue taking the picture after seeing the airplane.
 Flight 175 hit the South Tower at 9:03 a.m. The observation deck did not open until 9:30 a.m.
 The white balance of the two photographs are far off. If the plane were part of the photograph, it would appear more yellow.  This can be confirmed by comparison with the deck rail at the bottom of the photograph; the plane had nearly the same tint as the deck, while in the photo the two parts show obviously different in color.
 The poorly dated image appears to be one edited in MS Paint, rather than by an actual camera.

Later appearances

The picture became a widely known example of an Internet Meme. As its fame spread, other people started to use the same tourist for other pictures. They included the tourist present at the sinking of the RMS Titanic, at the John F. Kennedy assassination, the destruction of Air France Flight 4590 and at the Hindenburg disaster. In one version, the aircraft has been replaced with a Melbourne tram. Other pictures show him present at disastrous events in movies, like the destruction of the White House in Independence Day, Godzilla demolishing Tokyo, or as the bus driver in Speed. There are also pictures of him together with people from other famous photoshopped pictures, such as Bert or a man holding a huge cat. There even appeared a picture of the Yalta conference where Stalin is replaced by the man with the cat, with the tourist and Bert on the background.

Identity
The first person who claimed to be the tourist was the Brazilian businessman José Roberto Penteado. When Penteado started to get media attention, including an offer to be in a Volkswagen commercial, a 25-year-old Hungarian man, Péter Guzli, came forward as the real tourist. Guzli says, however, that he does not want publicity and did not originally release his last name.

Guzli took the photo on November 28, 1997, and was also responsible for the initial edit. He said he edited the image for a few friends, not realizing it would spread so quickly across the Internet. He first provided the original undoctored photo and several other photos from the same series as proof to a Hungarian newspaper. Later on, the show Wired News examined the evidence and confirmed that Guzli was the real Tourist guy.