thanks to Liam, I am now a xobni user. Xobni, reverse for inbox is an Outlook add-in that allows you to not only index and search your emails across multiple pst's (SSW had a free tool for this many years ago) but has interesting email intelligence tools integrated with it. You can figure out who is your number one contact based on email traffic, other network of people, times at which you are getting messages from certain people, etc. I think a server version of the tool is probably MS would want to plug into Exchange for their Social networking features.