Have a look at the video demo of http://www.sas.com/solutions/fraud/social-network/

Now imagine you could use this to track your stock investments, instead of your bank tracking your spending behavior and deposits.

And for the geeks out there, here's how that kind of stuff can be done, using the freely available R programming package:
http://www.r-bloggers.com/the-life-scientists-a...

And more articles: http://www.r-bloggers.com/?s=social+network+ana...

But who is this R guy, you ask?
http://www.infoworld.com/d/open-source/bi-battl...