Nielsen/NetRatings provides some very interesting data about Weekly (and monthly) Web Usage for both home users and those at work. Website Magazine will include one post each week highlighting this data - the following is for the week ending July 23, 2007.

Weekly Web Usage For Home Users:
Sessions/Visits Per Person: 10
Domains Visited Per Person: 26
PC Time Per Person: 09:46:18
Duration of a Web Page Viewed 00:00:48
Active Digital Media Universe: 117,049,872
Current Digital Media Universe Estimate: 212,080,194

Weekly Web Usage For Work Users:
Sessions/Visits Per Person: 17
Domains Visited Per Person: 42
PC Time Per Person: 19:37:48
Duration of a Web Page Viewed: 00:00:53
Active Digital Media Universe: 58,054,498
Current Digital Media Universe Estimate: 66,084,074