Royal Pingdom has a recap of 2009 web usage by the numbers. There are several nuggets - but here are a few that really stand out:

350 million – People on Facebook. 50% – Percentage of Facebook users that log in every day. 4 billion – Photos hosted by Flickr (October 2009). 2.5 billion – Photos uploaded each month to Facebook.

1 billion – The total number of videos YouTube serves in one day. 182 – The number of online videos the average Internet user watches in a month (USA).

247 billion – Average number of email messages per day. 81% – The percentage of emails that were spam. So: ~40b non-spam emails messages per day. YouTube alone serves 1b videos per day... amazing