Display: is it possible yet to collapse a set of non-custom data?
The easiest one would be with css. But that would not be collapsing them, that would be hiding them. You just get the id's of the fields and hide them. If they are not required that just works.
The 2nd easiest one would be with creating .extra.tpl files and doing it with jquery: https://civicrm.org/blogs/dave-greenberg/now-its-easier-add-custom-behaviors-templates. With jquery you should be able to make a collapsible fieldset.
The most robust one would be with a custom extension and share with all of us on github http://wiki.civicrm.org/confluence/display/CRMDOC/Create+an+Extension