If anyone is on twitter, set your location to Tehran and your time zone to GMT +3.30... Iranian security forces are hunting for bloggers using location/timezone searches.
It´s nice to see how people use the internet to organize the resistance, but it also scares the shit out of me somehow. Imagine those "security forces" when they have figured out how to use the internet for their goals. All the communication is public and stored somewhere, as well as the whole list of your friends. How easy it´ll be to round up all troublemakers in no time.