In 2005, a meme known as the "duckroll" began, after moot used word filter to change "egg" to "duck" across 4chan. Thus, words such as "eggroll" were changed to "duckroll". This led to bait-and-switch in which external links disguised as relevant to a discussion instead led to a picture of a duck on wheels.
In March 2007, the trailer for the video game Grand Theft Auto IV was released. Its immense popularity caused publisher' website to crash. An unidentified 4chan user applied the concept of the duckroll to what appeared to be a link to the trailer on YouTube, but instead showed the music video for Rick Astley's 1987 song "Never Gonna Give You Up". Thus, the "rickroll" was born.
Wikipédia, article détaillé : http://en.wikipedia.org/wiki/4chan#Rickrolling
Nota : moot = le créateur de 4chan, au cas ou vous ne le connaîtriez pas ;)
Edit : OMG http://www.youtube.com/watch?v=wL-hNMJvcyI
Rick Astley performing his own Rickroll ! Excellent, il manque pas d'humour non plus xD