Tor is the open source leader to anonymous connections on the internet, you can anonymize your internet presence from AIM/ICQ/MSN/ Jabber/IRC/WWW/FTP
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Vidalia is a cross-platform controller GUI for Tor, built using the Qt framework. Using Vidalia, you can start and stop Tor, view the status of Tor at a glance, and monitor Tors bandwidth usage. Vidalia also makes it easy to contribute to the Tor network by helping you set up and manage your own Tor server.