Twitter's now one of the few ways that protesters inside Iran can funnel news to the outside. And though there's a real danger facing those who do, you can make it harder for authorities to find them.
From Reunify Gally:
Do you twitter? Change your twitter setting to GMT +3:30 (Tehran time) and your location to any city in Iran. If all of us are Iranians then it is a little harder for government censors to track down Iranian tweeters. (See list of Iranian cities at http://is.gd/13UCt.)
Reunify Gally also has instructions on how to set up a proxy server to override blocked websites and allow Iranians to blog more safely.
-Kathleen A. Bergin