There are 2 ways to get user activity reports. First, if you are the owner of a folder, you can go to the "Manage/Activity Reports" menu and see all of the activity for that folder and any folder below it. In V2, this only gave you the activity of Team members of that folder. In V2.1 you hvae the option of seeing activity from all visitors to the folder or just the team members. The second way is to go to the site administration menu and use the "Reports/Activity By User" menu to get a report. This requires site administration rights.