Some statistics on Youtube found on Steve Rubels blog. http://www.micropersuasion.com/2006/08/youtube_by_the_.html

* In a single month the number of videos on the site grew 20% to 6.1 million

* YouTube has some 45 terabytes of videos

* Video views reached 1.73 billion

* 70% of YouTube's registered users are American, roughly 50% are under 20

* The total time people spent watching YouTube since it started last year is 9,305 years