There's a great first-person piece about the events up now on the New York Review of Books blog, describing, among many other things, this crowd chant:

“Christian or Muslim it’s not important, similar poverty similar concerns! Hosni Mubarak, Hosni Mubarak, the plane is waiting, the plane is waiting. Saudi Arabia is not far!”

To the question of what happened during that near-blackout of the media in the middle of the night on January 25, there is this answer:

Close to 1 AM, we sensed something was about to happen. The number of riot police had increased, we noticed more shielded trucks in outlying side-streets, and the security barricade the police had erected seemed to be inching closer, closing in on the square. Suddenly, there were groups of thugs—strongmen in cotton shirts despite the cold—both moving among the protesters and in the surrounding streets. The riot police pulled down their masks.

The attack was ruthless. The police fired round after round of tear gas and began to strike protesters indiscriminately with their batons; the thugs, who were beating down on protesters—in some cases with metal chains and knives—seemed to have orders to kill. With the air thick with sulphur, people fell to the ground, many toppled by the sheer force of the security forces moving in. Water cannons smashed through the crowds.

Hours later, many of us were back home, checking our Twitter and Facebook feeds for news and wondering what would happen next. Would there be a curfew, would the president release a statement, would the state concede anything? What would tomorrow’s papers say? People joked that the ruling family had just landed at Heathrow, a hundred bags in tow. Ayman Nour tweeted that his son had been detained. Activists slammed Hilary Clinton’s remarks describing Egypt’s government as “stable and looking for ways to respond to the legitimate needs and interests of the Egyptian people.” A picture of an empty tear gas canister circulated, the zoom focusing in on ‘Made in USA’. Organizers circulated a message that the protests would continue, tomorrow, the next day, and Friday after midday prayers.

“Don’t forget,” tweeted one activist, “that in Tunisia it took a month. #Egypt is bigger, it will take more. #jan25, keep it alive.”

At the time of this writing, protests have begun again...

UPDATE: Arabist has posted a woman's account of being beaten, dragged, and sexually harassed by protest police.