Contrib modules that use the Interface library include:
* Message Effects - add eye-catching effects to Drupal messages
* Interface Sortable - sortable list form element
Note: This project, much like the Interface library itself has been abandoned and is no longer maintained. Please look at JQuery UI as an more modern alternative. If you would like to take over maintenance of this module, please contact Jeff Robbins.
There is only a D5 version with this patch ot make it work for D6: http://drupal.org/node/208732#comment-1948478
Can you take over this project and communicate with the projects of Message Effects and Interface Sortable, so that they can work with the same features in jQuery UI ?! Or where else should this go?