SmugscopeCustomSmugmugUi
A greasemonkey script that removes default SmugMug Categories [or more precisely, whichever ones are defined in the categoriesToHide variable of function removeCategories()] from form select on create new gallery interface.
Other features beyond cleaning up the category dropdown for new galleries will likely be added in a future version.
Downloads
Source Code: http://wittman.org/projects/smugscopecustomsmugmugui/
Installer: http://userscripts.org/scripts/show/45261