From Josh Shahryar's live-blog summary:
I can so far confirm green protests in Tehran, Isfahan, Shiraz, Mashhad and Ahvaz. I can partially confirm a protest in Tabriz. I cannot say anything about numbers, but violence broke out in every city where I can confirm a protest. Dozens were arrested in Tehran possibly hundreds. 100 people were arrested in Mashhad and about two dozen were arrested in Shiraz and Isfahan respectively.
Oppostion leaders:
Mousavi: Attended, but forced to leave.
Rahnavard: Was attacked, forced to leave.
Karroubi: Attacked, forced to leave.
Khatami: Attacked, forced to leave.