In our comments, and in comments on other blogs, a number of people have been asking what they can do from here in the U.S. to help the Iranian protesters. Here's a small, easy thing that's being requested by Iranians who are using Twitter to organize:

Help hide Iranian protesters: change your Twitter location to Tehran, time to +3:30 GMT.

The idea is to confuse the Iranian authorities. If every Twitter user in the world is suddenly based in Tehran, that means a lot more accounts for Iranian security operatives to comb through as they try to figure out who to track down and threaten—or worse. (And hey, if even old Birch can figure out how to switch his Twitter location, surely you can too.)