Many websites that support user accounts, such as the ASP.NET Forums, include information as to how what users are currently online and what they are doing. For example, the Who Is Online page on the ASP.NET Forums shows the users currently online, what forum they're viewing, and how many minutes it's been since they were last active. Unfotunately the Membership system does not offer much in the way of tracking user activity. All it has out-of-the-box is the ability to log the date and time the user was last 'active' and to report the total number of users online - that is, the count of users whose last active date and time falls within a certain time window (15 minutes, by default).
With a little bit of elbow grease it's possible to track user activity. I use the word activity here loosely. An activity might mean visiting a particular URL, much like how the ASP.NET Forums Who Is Online page shows what forum the user is visiting. It could also be more broad. For example, if a user just updated their account information the activity could be logged as, “Updating account information.” The activity information of interest can be logged in a database table and, once there, can be used in reports, be it a Who Is Online page or a report detailing the activity of a particular user.
To learn how to log user activity and display the results in the aforementioned reports, check out my latest article on DotNetSlackers.com: Tracking User Activity.