Not much.
Almost anything anybody does, whether it be politician, newscaster, or even blogger, is seen as foreign meddling. Of course, any regime that has officially-sanctioned human rights abuses considers any comment as interfering with internal affairs. In the case of Iran, they do have a bit more justification for paranoia given the long history of other nations directly interfering.
I had a scheme to cause a minor disruption in Iran. It was not something that would put the country in a snarl, but something that, if enough people participated, would be noticed by the government. But I thought better of it. It would be "foreign meddling" and could provoke a similar disruption in other countries.
Many people are holding solidarity demonstrations, both peaceful and violent. If people in Iran know about them, they may feel others are supporting them. However, isn't that kind of news being suppressed? Besides, how much have anti-US demonstrations changed American foreign policy, even when a large portion of Americans sympathize with the demonstrators?
There are three things that Americans can do.
First, write to the President, your Congressional representative, and your state's Senators supporting the measured response that the President has given.
Second, donate to human rights organizations that are following the situation.
Third, keep yourself informed of developments.
Fourth, drive less! I almost forgot this. Iran is one of the authoritarian petro states. Oil is propping them up. If oil use declines radically, these states will have less funding and become weaker. Because oil prices have dropped dramatically from their eyes, they already have some severe economic and political difficulties. Less oil consumption around the world makes these states even shakier.
