Google Reader - my favorite RSS application - recently added a powerful search functionality that has made me infinitely better at studying people and their social patterns. Using Google Reader you can now search an individual feed, tag or a folder and get back a total item count, all sorted by date for as long as you have been a subscriber to that feed. In my case, some of my
feeds go back to October 2005 when the Reader first launched. That's a ton of data to mine for trends.
Now that my reader shows a huge cache of posts, I am subscribing to tons more feeds, stuffing them into a folder solely for the purpose of data mining them. The site also has limited set of advanced search operators. One hopes they will add more. It's worth noting that I don't actually read these high volume feeds. Rather, I mark them all as read so they get logged in my feed database and can be searched for insights.