Dancediplomacy is arranging a flash mob at the 6th of June - check it out:

Would you like to participate in a dance flash-mob on National Day of Sweden before a summer break? Then watch this video, learn choreography, send your registration to dancediplomacy@gmail.com and get all information needed about a rehearsal, location and time of the flash-mob! :) let's get some moves going on in Linköping!

https://www.youtube.com/watch?v=NIN5yZ-TGJI