For people, who would like to get to know the Berlin Web and Free Software crowd and also meet nice people and have a cold beer, I recommend the webmonday, Webmontag, at new.thinking. The founders of new.thinking and hosts of the events are Andreas Gebhard und Markus Beckedahl. The new.thinking store is located in the very center of Berlin, Berlin Mitte, in walking distance from Oranienburger Strasse and Hackescher Markt. The beverage prices are very reasonable (the event itself for free).
Of course there are presentations, for which you can put your name down in a Wiki and then you have the chance to present your ideas, your questions or success stories to an interested audience.
I met an interesting mixture of innovative companies as barcoo, fresh ideas – yes, I could imagine paying 3 EUR/month for a very good blog about Berlin – and Networking offers in and with Asia by a nice Berliner (Mario Behling).