I took part in a fascinating interdisciplinary meeting at the end of last week in Manchester looking at all diferent aspects of underground spatiality. Organisers Simon Marvin and Steve Graham brought together a good range of speakers (programme and abstracts here). Stand out presentations for me: Wayne Barrar's photographs of industrial underground spaces; Helen Scalway's talk on getting passenger's to draw sketch maps of the London Underground; David Pike's review of the forms of underground spaces in (Hollywood) cinema.
I gave a (slightly) modified talk on urban exploration (slides are here) and also chaired a session. I am working on completing the paper on 'space hacking' and will post it once a reasonable draft is ready.