I have been searching high and low for a module that integrates an accordion-style menu system in D7, similar to http://drupal.org/project/accordion_menu. Anybody know of one?
If the Accordion Menu module does what you need, consider helping the maintainer port it to Drupal 7. Here is an excerpt about it from the module's project page:
... will display a menu using a jQuery UI accordion effect.
- Multiple menu blocks, each separately configurable
- Menu source may be a Menu block sub-menu definition or a Drupal menu
- Setting to render the header menu item as a non-link (to avoid conflict between the accordion effect and the link behavior)
- Setting to not expand a header menu item even if it is in the active trail
- Setting for scope (see drupal_add_js())
- Settings for all published jQuery UI accordion options.
- Theme suggestions and template
- Multiple CSS classes including zebra, menu link ID, and count
DHTML Menu is great and it should work for what you need. I haven't used the 7.x version yet but they have a stable release. Here is an excerpt about it from the module's project page:
Ordinarily in Drupal, in order to see the sub-items in a menu, you need to click the link of this item and wait for a full page load. After enabling DHTML Menu, clicking a menu link once will expand it to reveal its sub-items without reloading the page. A double-click on the item will load the page normally. Additionally, a cookie stores which menus are open and which are closed, so that the state of the menus remain consistent as you navigate around the site.