Things go better when you know where you are. That is the theme of a fascinating exhibition which opens this morning at the Design Museum near Tower Bridge in London...The curator, James Peto, has assembled an impressive collection of designs "to help us understand the world we live in and to negotiate our way around it"...For sighted travellers to Japan, individual railway maps even show you where to sit on the train in order to be closest to the exit at your destination station. When you arrive and try to track down a particular location, you will find Japanese addresses are numbered according to a system impenetrable to most outsiders. Handily, cartographers have done their best to help travellers by producing street maps with pictures of individual buildings on them.