Cool (http://www.todayandtomorrow.net/2012/09/06/tube-map-radio/?fb_action_ids=3733326746624&fb_action_types=og.likes&fb_source=other_multiline&action_object_map=%7B%223733326746624%22%3A416023561793213%7D&action_type_map=%7B%223733326746624%22%3A%22og.likes%22%7D&action_ref_map=)
That's pretty clever, if it was portable enough and had a jack you could take it with you and navigate your way while listening to music :)