** Looking for Co-Maintainer of this module. Someone who keeps up with changes to CTools module. **
Panels Accordion provides an accordion display within Panels. By using accordions you can fit more content into smaller areas and allow your users to expand each section as needed. This uses the existing jQuery file for the accordion effect. The layout settings allow you to choose the action, effect, and speed for accordions.
The Drupal 6 version depends on jQuery UI (which is going into d7 core, so that dependency will go away). See UI Accordion for a more complete description of each of the options available in the pane-style settings dialog.
There is now a sub-module called Horizonal Accordion (see the demo), which depends on TextImage.