Tor is a program that allows people to bypass firewalls and use the internet anonymously. Communications from Iran are being actively filtered and they are trying to block some proxies too. As a human being I believe that censorship is wrong and that the people of Iran have a choice in who leads them. The rest of the world doesn't have a right to tell them what to do but we have a duty to help them be able to communicate and choose for themselves.
To get online anonymously and access blocked sites download Tor.
You can download Tor and the Firefox/Vidalia bundle here.
Run the program and tell it where you want it to extract.

Browse to extraction location and run Start Tor Browser.exe

You will now be connected to Tor and Firefox will launch.

Tor enabled will show in green in the bottom right corner of Firefox when it is ready to go. You should now be able to access filtered sites such as Facebook and Twitter. Facebook will ask for your birthday to confirm your identity but it will let you login. Be safe my friends.

Click settings in the Vidalia Control Panel and go to the Network button.
If you have a bridge link already paste it in the box and click the addition symbol.

http://git.torproject.org/checkout/tor/master/src/config/geoipplace it in:
C:\Documents and Settings\{username}\Application Data\Tor\

Check out Check out Why We Protest
Constantly updated list with leaked Iran videos. http://giagro.wordpress.com/torrents
Also try http://iran.sharearchy.com/ for information on getting around the Ayatollah's Iran Curtain.