A Consumer Data Device of a plastic encased, credit-card sized case containing a memory for data and transaction retention, an LCD display for displaying information, an LCD display for bar-codes to be read by a bar-code scanner, a controller to scroll through stored information, and a data communication...http://www.google.com.au/patents/US5789732?utm_source=gb-gplus-sharePatent US5789732 - Portable data module and system for consumer transactions
