Connect Berlin is an active group here in Berlin that meets regularly (I think more than once a month) with the sole purpose for people to get together, speak English and meet people (i.e. to "connect Berlin" as the name implies). If you are new in town looking to meet people who speak English, this is a great place to start.

The Friends of Italian Opera advertises itself as "Berlin's English Language Theater" and although English theater is regularly around Berlin if you know where to look, The Friends is one of the only theaters where they is a piece to see in English any given week. They just moved and continue to produce new stuff, check them out and see what's playing.

My friend Charles started organizing English events in Berlin and now has them almost every week where 30+ people gather to meet and greet. I was at a comedy a couple weeks ago, great entertainment, met a bunch of fun teachers from the Berlin International School, journalists, doctors, students, all working and studying in Berlin, wanting to practice their English and make contacts.

ELTABB is a professional association and resource group for teachers of English as a foreign language and other English language practitioners in the Berlin-Brandenburg area. We have workshops for teachers every month, a Stammtisch where members can meet and a Winter and Summer Party. The mailing list is also very useful for job leads and when you have a question about teaching in general or specifically about teaching English in Berlin.