Would be interesting to compare writing styles, format etc of users on forums.  Would be interesting if we could identify users with multiple accounts.  Also, would be interesting to look at the change in style over time per person to see if it was hacked or something out of the ordinary.  Plot emotions over time.  Would be interesting to see who has the emotional sway (can cause others to become emotional etc.) over the forum or post etc.  I wonder how much there is in this area.  I would imagine it would be a lot since we have had forums for a long time and I think this is something that Facebook has (or should be) been doing.