The present invention provides a method of enabling a first user to obtain, using a business card of a second user, authority to transmit electronic mail to the second user, the business card including coded data indicative of the identity of the business card and of at least one reference point of the...http://www.google.co.uk/patents/US6963845?utm_source=gb-gplus-sharePatent US6963845 - Business card as electronic mail authorization token
