Thanks for the reply!

I found the Community extension shortly after I posted this.

However, there seem to be some limitations and bugs.

One particular bug: If you limit the diskspace per user at all, the user will get an error that their browser doesn't support HTML5 instead of displaying the upload box.

There is no way for a user to add a description and tags when they upload. And no way for the user to see their files after they've been uploaded (apart from trying to find them in the gallery normally).

The user also isn't notified when the admin approves their images.

Basically there is no continuity between the user and the images they upload. Which means the administrator has to try and track down every description, tag, etc when someone else uploads something.