Sure anything is possible...
So how are you going to have them turn off the coums? Form, or HTML Link?
Either way you are probably looking to dynamicly create your SQL statement, to only select those colums which the user wants to view. This can be done as simply as
$sql = "select ";
if showX {
$sql .= " first_name";
}
.
.
.
As for the table headers, well all you have to do there, is to echo those headers for the colums you want to show, and nothing for the ones you dont...
Hope this helps...
PHPdev