I just returned from an 8-day trip from my home in the US, in Wisconsin, to Berlin. The trip was mainly business, but my wife and I arrived a few days early to explore. Here are a few random thoughts.
Ideas for future GermanPod101.com cultural topics and survival phrases:
(1) tipping. Who do you tip (e.g., waitresses, cab drivers, hotel bellmen), and how do you tip them (e.g., don't leave a tip for a waitress on the table), and how much do you tip them (one person told us "no more than 5%," but I don't know if that's just his opinion)
(2) how to get euros. We used ATMs, but they aren't nearly as prevalent as in the US, and we had trouble even asking people where to find them. I had been told to call them "ATM-Stellen", but some people didn't even know what that was ("Cash Automaten" turned out to be a better phrase).
(3) talking to policemen and security people. In Germany, people in those positions were generally all business and seemed very annoyed when we asked for directions or something similar (although nearly all other Germans were very helpful).
(4) survival phrase idea: "Was haben Sie vom Fass?" ("what do you have on tap?") Definitely an important phrase to know. And Chuck, you're right, Radeberger is excellent (but so are Berliner Pilsner, Berliner Kindl, Wahrsteiner...)
(5) ziehen und druecken (pull and push). Most doors in the US pull, but not so in a lot of the places we visited.
Some of the cultural information I learned from GermanPod101.com prior to the trip was very helpful. Bicycles are indeed everywhere, and if you're standing in the red brick bicycle lane, you are taking your life in your own hands. It was also helpful to have learned in advance that there are many people who do not speak English. Nearly everyone who is young did speak English, but we encountered some people who have a lot of contact with tourists who do not speak English (for example, at a couple museums). Even though limited, my German language skills came in very handy in those cases.
Part of our stay was in Potsdamer Platz (all newly rebuilt in the last 9 years, and hideously expensive), but my favorite parts of our trip were when we stayed outside the Mitte, exploring other parts of the city on the S-Bahn and U-Bahn. It's a fascinating city.