Irantracker.org, from the American Enterprise Institute, is keeping track of protests and other incidents of unrest following the presidential election in Iran with this interactive map:
They also have day-by-day statistics for numbers of protesters, arrests, and deaths. They claim a total, through Thursday, of 33 deaths, 661 arrests, and more than 1.3 million protesters. They also have a lot of information and analysis on the political situation in Iran.
Via Andrew Sullivan, who's done excellent work following events in Iran and who's obsession with the situation has been feeding my own.