Private Conversations is a small mod that adjusts the way your PMs are displayed; Instead of the old method which shows one at a time quoting the last message, this threads them and makes them work much like the Conversation feature that visitor messages use. A conversation is defined as two users PMing eachother using the same PM title (With or without the "Re:" prefix), so as to not mix up different conversations that aren't related.

Usage
Private Conversations is entirely automatic, no configuration or installation required (Other than the above). Upon visiting the "Private Messages" page, this mod will automatically list conversations. To see normal PMs instead of conversations, simply select a folder at the top menu (Such as "Inbox") and Private Conversations will let the default view take over; It will always allow MHU PM system priority over itself whenever it detects that the user has selected a folder.
A reply box will show at the top of each message, allowing for easy replies. You can also select 'View Full' on each message to see it in the old format, which you can also reply to using the old method. All messages apart from the three latest are automatically collapsed inside conversations, to save page space.