Black Spirit

I'm planning to go to Berlin with my boyfriend in two weeks :D That will be a lot of fun ^_^

Of course, I want to visit the usual Berlin (Mitte, Alexanderplatz...) and spend some money in some material stuff that I don't have in Belgium (X-tra-X for some shoes, Saturn for the music...) but I also want to visit the "underground" Berlin, too. My boyfriend is not... an "undergournd" person ^_^. So I hope I will be able to visit the places I want to see :).

"Underground" in French means something which is not "usual". For instance, listening to batcave music is "underground" when pop music is "mainstream". I don't know how to say that in English :/.

I would like to go to Friedrichshain and some squats, to know better another Berlin that the travel agency don't show us. I would like to go to Tacheles, Rauhaus too.
I found two website which are pretty interesting:
http://stressfaktor.squat.net/
http://unitedwestay.noblogs.org/

On Sunday, I would like to go to Mauerpark to see the secondhand trade which seems famous.

If you have some good addresses in Berlin (food, bar, expositions...) don't hesitate to tell me ;)