Mark my words, this incident will inspire a tidal wave of mashup videos similar to what the 'Bus Uncle' clip (read the Wiki entry about the incident here) did few months ago. Already, there are mashup videos in Youtube like this and this (the latter video's kinda gross) in Youtube. So expect to see many variations of this incident, possibly an 'epic version', a Brokeback Mountain version, an orchestra version, a fake prequel with dubbed voices, etc etc. We are living in an age where everyone can be creative, and anything they create can be distributed around easily over the Internet.
The above quote came from my Salute to Zidane entry two days ago. It's incredible that my prophecy is fulfilled almost instantly, and Zidane's headbutt has totally become an internet phenomenon. Insanely creative animated GIFs, parody videos are already spreading around like wildfire across cyberspace. Yep, this incident has invaded pop culture around the world, much more so than Italy's supposed glory and victory it had attained during the World Cup.
(Hell, does anyone still remember that Italy had just won the World Cup? Or that Materazzi was the guy who scored the equalizer in the match with his header, and not just the guy who got headbutted by Zidane?)
The animated gifs below are from Something Awful. I have a huge load of them, but I can't really upload them here due to space limitations from most image hosting services like tinypic.com and photobucket.com.
On the other hand, you can download the torrent for 32mb worth of Zidane's headbutt animated gifs.
Here are some videos obviously inspired by Zidane's headbutt.