I am in the webcast by Heidi Hewett right now. It is packed with over 200 attendees but you might be able to still sneak in.

Migrating Menus and Customizing the AutoCAD 2006 User Interface
Thursday, September 29, 2005 | 10:00 a.m. PDT (1:00 p.m. EDT)
See how simple it is to import your AutoCAD MNU files into AutoCAD 2006. You'll also be shown how to easily customize your user interface with the new XML-based menu format.

www.autodesk.com/AutoCAD2006SeeIt

If you miss the sessions, they should be made available for download about a week after the session.