BuddyPress.org

Hey this thread might be a little bit old.. But I wrote up a tutorial on adding menu items, drop down menus, & drop downs with flyouts Via a plugin so its all upgrade safe.
The link is here:
http://erikshosting.com/wordpress-tips-code/adding-custom-menus-links-flyout-dropdowns-to-the-buddypress-bar/

Here is another tutorial on how to remove the downward facing arrows from certain bp menu items:
http://erikshosting.com/wordpress-tips-code/remove-buddypress-bar-arrow-images-from-menu-links/