That's right, I am finally registered as a resident of Berlin. After two failed attempts (note: don't put your moving-in date as a future date), I guess you could say it had become the bane of my life; being technically still a tourist prevents you from doing quite a lot.
I got up early to travel to the Bürgeramt at Rathaus Neukölln. Unlike most of the city's Bürgerämter, you can be served there without booking an appointment weeks in advance, but you still have to arrive in good time in order to be seen that day. I got there 40 minutes before opening time and there were already a good couple of hundred people in front of me:
After the opening time itself, I waited another 30 minutes or so to get an appointment number. It was set for three hours later, and some people I'd met in the queue - Humboldt students from Ireland, Bulgaria and Mexico - invited me back to their place for lunch!
We got back to Rathaus Neukölln and sat in the waiting room, where numbers appeared on a screen. When I went up to the desk, the person I spoke with was very friendly and even complimented me on my name! Despite the frustrations I have had to go through in order to even get an appointment, the procedure itself only took five minutes. I just had to show my passport and a form I'd happened to have previously filled out (and had asked my housemate to countersign). You may need to take a flat/WG contract with you, though, and I'm only speaking as a citizen of an EU state.
So, all because of a piece of paper, I'm feeling a little more settled in. Looking forward to joining the library and receiving my tax card!