I went to Berlin for the 27th Chaos Communication Congress. My flight was late, my plans uncertain, and I didn't bother to get a ticket in advance, but despite all these setbacks I was able to get in with a four day pass strapped to my wrist within a couple of hours.
I've dented (read as "tweeted") most of my major take home learnings, so I will spare you a blow by blow. By the fourth day, incessant talk about wikileaks and mounting claustrophobia had taken their toll, and since I had misplaces my pass anyway I decided to spend the last day wandering around Berlin instead, checking out the art.
I followed my instincts to the canal and the train tracks, where I found an incredibly rich trove of stencils, graffiti and wheatpastes. The nice thing about underpasses and train tracks is that people really take their time on them, so you can find some incredibly nice pieces on the walls. Apparently, Berlin is one of the most painted cities in Europe.
Feeling good about my use of my last day in Berlin, I finished the night flitting between my hostel and various parties, waiting for my 7 am flight.