Wikimedia Bugzilla is closed!

Extension request: 
The extension provides a Special page which can be used 
for users to request access to a privileged user group.

It can only be used by emailconfirmed users
(a nice message instead of 'permission denied' if it is not, 
would be preferable but not required)
The user submits a form there to be "upgraded" (there could be 
an optional message), the extension stores a token to this 
request in memcached and fires an email -including the username 
and its email- to the gatekeeper, which manually checks the 
user email is in a secret approved list and if so, can follow a 
link provided in the email, and the user is automatically added
to the cabal group.
It would be nice if the user received an email on approval, too.

Although I only need that for a single group, it would be nice if 
it was flexible enough to provide several groups (ie. you wouldn't
need to copy the extension and modify it if you wanted one group
for 'staff' and another for 'contractors').