TrueCrypt
From Cship
TrueCrypt is a free ad open source software used for encryption for Microsoft Windows, Linux and MacOS. It can create a virtual encrypted disk within a file, so once you started TrueCrypt and mounting the file by entering your password, you have a new "hard disk" called for example "X:\" which you can use like any normal partition/hard disk (saving documents, installing programs...).
If you fear from beeing catched using circumvention technologies to bypass Internet censorship, you should use a disk encryption software like TrueCrypt.
The current version is 6.2a from June 2009.

