From CNEWS:

Citizens of countries such as China and Iran are about to be handed a powerful Canadian-made tool designed to undermine authoritarian efforts at stifling the free flow of information.

Called Psiphon, it’s a small computer program that allows people in non-democratic places to beat the local thought police and access forbidden websites at minimal personal risk.

……Currently, the program works on Windows and Linux operating systems, with a Mac version in the works.

It can be downloaded at http://psiphon.civisec.org. [Full Text]