BB

While Drupal specializes in simplicity, competing with forum software like phpBB or Invision requires more depth in terms of individual pieces. One of the most underdeveloped modules is, without a doubt, the private messaging module. Compared to other types of PMing, this module can certainly be expanded. What do you think could make PM-ing more interesting for users on a site?

My ideas:

Folders: Letting users create folders for their PMs would certainly add a needed feature. On some sites (no Drupal ones I use, but certainly on forums), I receive a ton of messages, so letting me sort them is certainly a convenience.