New forum features: "Your Notifications" menu and vbulletin 3.7 beta 5
I have just updated us to vbulletin 3.7 beta 5. With beta 5 we get the new Conversation feature; a means by which visitor messages posted between two users on each others' profile pages can be viewed in a unified form. Look for the 'View Conversation' link on visitor messages to use the feature.
Also I have enabled the "Your Notifications" menu which should make tracking of social groups and other parts of vBulletin like PM's. You can find it in the top right corner after you login (only when you have a new PM for example) and it provides a quick way to see what pending requests you have.
That area in the top right will also highlight itself when you have a new notification until you clear it although this part may be tweaked later.