A Year of YouTube: cat
All the thumbnails of videos matching the tag "cat" submitted to YouTube over the past year. About 33,300 in all. The thumbnails are placed on the graph to create a heat signature showing the rise in activity at YouTube.
Vertically, the thumbnails are positioned by the time-of-day they were submitted, and horizontally by the day of the year.
As you can see, YouTube has seen phenomenal growth over the past year.
More stuff by jbum: