Tonight I started testing out Xoopit, a web-service that integrates with your Gmail account and organizes the social content within. It's in early development, and so it has limited features and only seems to index the most recent few months of my email, but the results are very cool. Now I can browse through all of the photos attached in my email like they're a photo album. I can also view all of the Youtube videos that have been linked to in emails, and see a list of all of the files that have been attached. This essentially indexes, archives, and organizes all of the media associated with your Gmail messages. Right now this basically only works for YouTube, Flickr, Picassa, Shutterfly, and Kodak, but more support will come and I'm sure more features will come. Also, there is no detailed information about the actual contact with your friends, such as seeing send/receive rates, response times, etc. There is some "info stream" and content prioritization if you log in to your account on the Xoopit website, but this should all be integrated into Gmail.
So far Xobni doesn't seem to have broken Gmail or slowed it down. It leaves itself pretty un-intrusive up at the top of the Gmail interface. If it continues to show no negative impact on my email consumption, and doesn't break after a few weeks (like other Gmail integrated extensions), it has a chance to be a mainstay. I'll report back on my experience overall.
A few months ago I tried out a service called Xobni that completely wowed me right at the start. It did similar things stripping out and organizing media, but more importantly it brought "conversation view" that is so popular in Gmail directly into Outlook. It also provided instantaneous search, and showed social information around contacts such as what I listed above in a wish-list (quantitative rankings, response times, etc.). The biggest feature it had was that it identified the phone numbers and addresses that people included in emails and filled this information in on the contact cards within Outlook, almost like magic. Xobni had a chance to revolutionize Microsoft Outlook, and it still could, but unfortunately it slowed Outlook to a crawl, and given how slow it is already with company-server integration, Xobni's negative impact in this area forced me to un-install it despite all of it's other great features. Hopefully Xobni and Xoopit both continue to grow in feature set and become more efficient.