The autodelete account module is designed to enable certain roles and of course users within that roles to auto delete his own account. By default this option is only enabled to admin users in edition user mode.
0. Download the module and rename 1267268 folder to autodelete_account. see note.
1. Install autodelete_account module.
2. Set the permission ''delete own account' to the roles you want enable to delete his own account.
3. Inform your users that they can delete his own account.
Note: the author made a mistake creating the project, so the zip download is 1267268.tar.gz or 1267268.zip. if you know how to rename a short project name, please let me know. Issue report at http://drupal.org/node/1267356
This option is useful for sites with subscription and maybe that sites are a kind of spammer, then users can decide when delete his own account without administration supervision.
If a regular user delete his own account , this operation doesn't have ROLLBACK, all content related with this user will be transfer to anonymous user.