Lodging
Please check this alternatives to get a nice and cheap bed at night:
https://www.facebook.com/groups/114407341968047/
https://www.facebook.com/groups/547530108636607/
https://www.facebook.com/groups/292186250836587/
https://www.facebook.com/groups/890919300923458/
https://www.facebook.com/groups/251856141592447/
https://www.facebook.com/groups/781863541850952/
https://www.facebook.com/groups/666822796665326/
https://www.facebook.com/groups/1405075999765354/
https://www.facebook.com/groups/wg.wohnung.berlin/
https://www.facebook.com/groups/wg.wohnungen.berlin/
https://www.facebook.com/groups/easy.wg/
https://www.facebook.com/BerlinWgZimmer/
https://www.facebook.com/groups/roomsurfer/
http://bedandtango.com/en/search-offers?search_api_views_fulltext=berlin
http://www.ebay-kleinanzeigen.de/s-auf-zeit-wg/berlin/c199l3331
http://berlin.en.craigslist.de/search/apa
http://www.couchsurfing.com
http://www.hospitalityclub.org
http://www.bewelcome.org
http://www.globalfreeloaders.com
http://www.tripping.com
http://www.gloveler.de
http://www.belodged.com
http://www.roomorama.com
http://www.wg-gesucht.de/en
http://www.wg-gesucht.de
http://www.studenten-wg.de
http://www.airbnb.com
http://www.9flats.com
http://www.wimdu.de
http://www.housetrip.com
http://www.booking.com
Some proposals for hostels if the workshop happens in Kreuzberg:
http://www.grandhostel-berlin.de
http://www.acamaberlin.com
http://www.jugendhotel-berlin.de
http://www.berliner-bed-and-breakfast.de
http://www.metropolhostel-berlin.de