P2P Research Institute
URL = http://p2presearch.com/
"It is estimated that BitTorrent alone accounts for 18 to 35 percent of all traffic on the Internet. The colossal scale of the file-sharing network has defied deep analysis - up till now. The Peer-to-Peer Research Institute conducts real-time and historical quantitive analysis of p2p networks, develops cutting edge Open Source software and publishes papers, reports and guidelines for this difficult-to-track domain."