As you may or may not know, FaceBook gives you the option of hiding your online status. It’s located as an option within the footer chat box. Simply open the chat box, hit options then click ‘go offline’. This effectively makes you invisible to your connected friends.
There is a way to easily find out how many people are hiding their status. For this to work you must physically log out of FaceBook (by hitting the logout link), then log back in. Once logged back in don’t click anything. Simply have a look at your friends list on the sidebar then compare that number to those in the Chat applet.
This example shows 2 more people in the chat applet than there is on the sidebar. This indicates that 2 people are hiding their online status. If you click the chat applet, those extra two friends in the count will disappear and the sidebar and chat applet will then match.
This will only show you how many friends are hidden, not who they are.
Also keep in mind the date of this posting. This small glitch my be fixed or could disappear the next time FaceBook rolls out there newest page layout.
This likely falls into the category of ‘useless information’ but thought I would post it anyway. I found it interesting.