It is part of a "guerrilla geography" experiment, in which citizen geographers impose their own stories on the map. You have heard of citizen journalists challenging the mainstream media - now, mainstream geography is being challenged.
Thus, Manchester's new map will no longer document the growth of the world's first industrial city, the birth of the suffragette movement or the establishment of the world's first professional orchestra. Instead, it may record that under a particular monument, aspiring geography teachers Jim and Jane first ... in fact, let's just leave it there.
The Guerrilla Geography Network is organising the Beyond Naughtiness event this weekend to coincide with the Trip2008 geography conference. "Ultimately, this information will be used to map Manchester's geography of naughtiness," the group said.