WordPress.org

Starting in WordPress 2.7, a menu is included in the upper-right corner of the Admin. The menu, by default, includes links allowing easy access to frequently used pages in the Admin. But there isn't an option to add your own links!

Favorites Menu Manager allows you unfettered customization of that dropdown menu. You can easily add your own links, remove existing ones, and put them in the order you desire. Customizations are stored on a per-user basis, so each user can have their own collection of frequently used links.