I’m a Linux user in China. I used to run Freegate on Windows for the great proxy issues. Unfortunately, I can’t find a solution as good as Freegate for Ubuntu. Bite makes life a lot harder.
TOR (http://www.torproject.org/) is one option for Linux, although you should make sure not to act as an TOR server yourself because people might use the network, thus your Internet connection for bad things.
Other then that I suggest a visit to http://www.sesawe.net which offers informations, tools and support for censorship problems.