From The Toronto Star (link):
Revenge of the nerds Three computer geeks at the U of T are renowned developers of anti-censorship software, including a program out this month that could allow people to outwit the world’s most repressive regimes.
…… The program effectively turns anyone’s personal computer into a proxy server. Once the software is installed on a computer in, say, Canada, that person creates a contact list of trusted friends or family members in censored countries and sends his or her IP address to them. No advertising needed.
The censored user then connects to the computer running Psiphon and accesses banned content from there, all unbeknownst to the censor.