BackType (YC S08) Analyzes 30 Billion Tweets To Measure Twitter Engagement
mashable.com
mashable.com
http://googleblog.blogspot.com/2010/04/replay-it-google-sear...
"For our initial release, you can explore tweets going back to February 11, 2010, and soon you’ll be able to go back as far as the very first tweet on March 21, 2006"
It's not about how much data, it's about how you utilize the data to obtain meaningful results.