That brings me to custom profile fields(if implemented). Same concept. Allow the admin to create a custom profile(each with it's own ID), and allow those to be added to groups too. For example, have a custom profile fields that says "Occupation" with options "Plumber", "Programmer", "Milkman", etc etc. Then the admin can create a group that gives "programmers" permissions to access a programming board, or other mods such as a shoutbox, etc. Whatever permissions are set for the group.
Custom Profile fields are just for information only, unless the admin chooses to add a custom field selection to a group that is created.
Just a thought...