SharePoint 2010: Who is Connected on my SharePoint Server?
Performance Monitor
More and more SharePoint Administrators want to see, how many users are connected before they can shut down their server for Applying Updates or anything else! I heard, many people talking about sandbox solutions or many other things, but there is a wonderful tool in Windows Server "Performance Monitor"
Select WebService and go to Current Connections. Now select you're site, and add this counter!
Gokan