It is now very common to see a number of features on panels on websites that would be a good addition to portlets. One of these is expand / collapse buttons. They should work using AJAX but also with Javascript disabled:

* Link to collapse a panel so that just its heading is shown.
* When collapsed link to expand panel to original state
* Requires two fields for a portlet: Collapsable (Yes / No); Starts Collapsed (Yes / No)
* Should also be a site property to control how long the expand / collapsed state of a portlet is remembered for a client (request, session, forever)
* I think this should be added to all portlets delivered with Plone plus easily addable to custom portlets