Thing #1: A Gangnam Style Flash Mob in Piazza del Popolo. While I was probably getting for bed after a busy day at home, this was happening just a ten-minute tram ride away. It was huge! I'm surprised I didn't hear it from the apartment.
Thing #2: High water in the Tiber. The river used to flood regularly and wreak havoc on the city, so now there are high embankments on either side. I don't think it's in danger of flooding its banks, but it's still pretty spectacular to see (and I did actually seen it, but only from the window).
You can see more pictures of the high water here.
I'm thankful for the Internet so I can keep up with happenings in my own backyard.