Gangnam Style hits one billion views on YouTube
21 December 2012 Last updated at 16:54 GMT
Gangnam Style has become the first video to clock up more than one billion views on YouTube.
The South Korean dance track was posted online in July, propelling pop star Psy to worldwide fame.
It has inspired hundreds of parody clips, from members of the British army, David Cameron and President Obama among others.
The BBC's Rory Cellan Jones reports.