Managing user roles in Drupal is easy -- at least, technically easy. It's a bit trickier if you have a large user base and need to manage a steady stream of people requesting access to specific privileges, new roles, or additional responsibilities. If you're in that situation, get ready for some quality time with your email client, and set up a regular appointment with Drupal's User Management screen. Fortunately, the Apply For Role module can simplify the process.
With Apply For Role, users can visit a new tab on their user account page and request access to a new role on the site. The request is queued up for an administrator, who can review, approve, or deny requests from a central management page. Requests can also be deleted -- allowing the original user to re-submit their request later -- or denied, ensuring that they can't send in more requests for the same role.
The module allows site builders to set up which roles can be applied for (to prevent users from getting a glimpse at roles they should never have access to), prevent or allow multiple simultaneous role requests, and so on. For site builders who want extra control, the module also provides full Views integration, as well as integration with Trigger module. You can easily build a custom administration screen to manage role applications, complete with notification emails.
There are a few noticeable gaps in Apply For Role's functionality. The application form that users fill out is spartan and lacks any explanatory text; giving administrators a way to add more help text to that page would go a long way. In addition, it would be great to customize the names of the roles that are presented to applicants. Most sites' roles are never shown to normal users, so they're often named for brevity rather than clarity. Both of those oversights can be remedied with some minor hook_form_alter() work in a custom module, but it would be great to see them integrated. Even without those wish-list items, Apply For Role is a slick solution to the problem of processing large numbers of permission-change requests. If your site's user management workflow is a good match, you should definitely check it out.