As for me, I was headed home after my class and started heading down Parkveien (the road behind the palace), when I started noticing a log of police cars and some sort of barricade down the road. Needless to say, I had to backtrack and walk through the park around the palace to get home, and I saw that the police had a couple of roads blocked off in the area around the Israeli embassy. Apparently officials estimate the damage to be in the millions of Kroners (broken windows, damaged police cars, etc.).
On Friday there was a more peaceful protest that went past work - lots of shouting and a police escort, but no rioting. And on Saturday a window was broken at a McDonalds - apparently there was a rumor that they were donating a day's profits to support Israel (yeah, like a company would do that, but it just goes to show how stupid people can be).
Note: Photo credit listed as AFP.