gmap google maps

In admin->user settings->permissions->gmap, there are 4 types of user permissions:

I think I understand the first 3. But what does the 4th one mean?

Thanks.

I would like to try and make an interactive menu using drupal and gmap that involves using check boxes. If you check a box, the markers show up on the map... this site is an example of the functionality I am trying to reproduce: http://www.wimaxmaps.org.
I'm not sure where I would build the check box form right now. would I use the menu system or what?
Has anyone tried anything like this?

Becky