Last year I was in a shared room and it was massive. Next door was the same. One of my neighbours went out for a field trip one day so we moved everything (yes everything, bed, desk, wardrobe, posters etc) from his room into ours and pinned up a fake (but official looking) letter from the university saying his stuff had been impounded and that he had to pay his fees at the finance office before he could get it back. Of course it was all in my room nextdoor!!
Oh, and there was one girl that loved shoes and had hundreds of pairs. So we took every single left shoe from her room and lined them up in someone elses. That was amusing.