As the government in Tehran tightens the grip on the internet access for the people of Iran, the natural question for people living outside Iran becomes:
Is there some way I can help the people of Iran get uncensored internet access?
If you know your way around a computer, and have access to a stable internet connection, there is.
One option is to set up Tor. Tor uses onion routing. Onion routing secures that you may know that I sent (or received) a message on the network or you may know the content of a message, but never both.
As discussed here the number of Tor users from Iran has increased quite a lot since around June 13, so it would seem like Tor is actually being used in Iran.
Tor can be downloaded here, but does require a bit of configuration after install.
If you want to benefit from the anonymity provided by tor, you need to start sending your internet traffic through Tor, and in general familiarize your self with the pitfalls that may break your anonymity.
If you have a fairly decent internet connection you might want to consider becoming a relay from the Tor network to the outside. Information on that can be found here.
There are of course many other ways of fighting censorship (both in general, and in Iran in particular). Feel free to share info about other ways or projects in the comments below.
Warning! Running Tor may be illegal, depending on what laws apply to you. Also notice that while running a relay can help people, who suffer under censorship, communicate freely, you may as well be helping route data for people with less noble goals.