Email has oft times been called the "killer app" that drove exponential growth of the Internet, but I'm fascinated by how little my "email experience" has changed over the last 10+ years. My workflow for writing and reading email in Outlook 2003 at work is little different than the workflow I followed when I first started using email on bulletin boards in high school! The last major change in the way I handle email came when I switched over to Gmail for all non-work email two years ago - I now use tagging and search to manage email. In fact, Google Desktop has done more to change my work email habits than anything in the Outlook client - I use just a few folders to hold all email and simply search to find what I'm looking for.
Xobni Insight piqued my interest when I read about it in this Lifehacker posting earlier today. I've read postings in the past about attempts to apply a social network approach to organizing and presenting email, but this is the best realization of that concept I've seen to date. Xobni Insight is currently in limited beta for Outlook 2003/2007 - I've signed up and I'm anxiously awaiting an invitation to give it a try. I'll follow up with a posting about my experiences with Insight once I have it up and running.