HuffPo contributor Josh Shahryar has been a reliable source:

Status Update15: Rumors of Zahra Rahnavard attending protests in Tehran - can't be confirmed

Status Update14: No major reformist leader was present during the protests.

Status Update13: Clashes in Shiraz and Hamedan - many injuries in Hamedan

Status Update11: Outside Tehran, number of protesters in most cities in the hundreds and not more.

Status Update6: Number of protesters in Tehran between 5,000-10,000

Status Update2: Confirmed Protests in Tehran, Mashhad, Shiraz, Isfahan, Kerman, Kermanshah, Arak

ABC News' Lara Setrakian adds:

Speaking to students sunday, Rafsanjani called for a 'climate of freedom' in #Iran, accusing leadership of intolerance

Opposition supporters say yesterday's Rafsanjani speech was 'very, very important timing' ahead today's student rallies

Veteran twitterer Omid Habibinia is still going strong, and also live-blogging for France 24. Here he relays a dramatic account from an Iranian on the ground:

I'm stuck at the Talegani and Valiasr crossroads. The police and the Basij (the Iranian citizen militia) have closed both sides. The Basij are beating people with batons. There are a lot of people, certainly more than on previous student days.

They're coming! [She's starts running].

There are people at the Enghelab [Revolution] Square.

And there are clashes at the Talegani and Valiasr crossroads.

They're arresting a lot of people and leading them away, but people are trying to rescue them.

We've just stopped a Basiji and stolen his motorbike near to Enghelab square."