As you can see from this photo, some 5,000 naked people gathered outside of the Opera House in Sydney, Australia for Spencer Tunick's latest photography project. The Sydney Morning Herald has a silly write-up and many more photographs, some of which are potentially not safe for work.Tunick's art plays with the line between public and private life by placing scores of naked human bodies together in public spaces. I imagine some people consider his stuff old hat at this point, but I'm generally impressed and amused by him, and the Sydney edition is no exception.It would be rather exhilarating-if nerve-racking-to stand in for one of these pieces. Would you pose nude for Spencer Tunick?