The weekly look at the world of information technology - with Fred Harris and lan MeNaught-Davis.  Finding your way around a computer system can be frustrating; psychologist Professor David Canter explores the endless corridors of unfriendly operating systems.  All software great and small in a country practice - vet John Drew 's specialist business needs.  And a look at Life-Card, a new kind of 'read/write' optical storage device on a credit card. It's soon to be introduced into the wallets and purses of 85 million  Americans to hold medical information which could be vital in an emergency.