I assume you are talking about islands. That is what the features are called such as the items on the right here.(Search,Who's online,Shoutbox)
If you enable the pertinent members settings in the control panel a member can elect to hide the left side or the right side or both sides.
But a user can't decide to exclude just the shout box as an example for this site.
This user ability appears to be disabled at this site from the control panel.
Last edited by Ruben Rocha; 12/25/2008 6:59 PM.