Hi, I have just listened to the contribution to the BBC "With Great Pleasure" series by Simon Singh. He who writes books on Cryptography. If you like the idea of 30 mins of gentle humour with a Scientific touch, I commend it to you. http://www.bbc.co.uk/iplayer/episode/b012qsdh/With_Great_Pleasure_Simon_Singh/ It will be on the BBC pages only until Tuesday. Brian G2KQ