A suggestion for folks interested in personalized walking tours in Berlin:
Ours with Jeremy Minsberg (www.theberlinexpert.com) was the best tour we've ever taken. Jeremy was smart, funny, thoughtful, patient, and he even knew when to say "I don't know" in response to a question. He even followed up our tour with suggestions for books to read and films to watch if we were curious. In short, we came away with more in our 4 hours than we could've gotten on our own. What more could we want from a tour?
Our experience with tours -- be they big ones, say, at museums or personalized for a small group -- is they're disappointing. The typical guide is windy, slow, repetitious, and asks superfluous Qs like where everybody's from (who cares if the other couple is from Des Moines?!). Jeremy knows better. And even though we know he's done this countless times before, he brings the energy of someone who seems to still get a kick of exploring around and commenting on his adopted town. He reminds us of your best teachers. We cannot recommend Jeremy highly enough.