Abstract: Access to stored information by a user is controlled by comparing an actual geographic position and/or an actual date/time with a geographic region and/or a date/time interval within which access to the stored information is authorized. The actual geographic position where the stored information is located, and the actual date/time can be determined, for example, based on signals received at a receiver supplying reliable position and time information, such as a GPS receiver. Access to the stored information is authorized if the actual geographic position and/or date/time falls within the authorized geographic region and/or date/time interval. The position and date/time information supplied by the receiver may be cryptographically signed and encrypted.

Abstract: Hierarchically organized graphical representations of items and groups of the items of digital information which are available to be ordered by a user are displayed. The user interactively explores the representations and selects items or groups to be ordered, using a pointer. While the graphical representations are being displayed, a list of items or groups which have been selected for inclusion in an order is also displayed. Software is executed which automatically determines the configuration of the computer, and matches the configuration with the stored configuration information prior to the user placing an order. A user may automatically be given access to items in a later revision of the medium if the user had access to the items in an earlier revision.

Abstract: In a merchandise checkout system including an electronic cash register having a touch screen panel and a cash till including a plurality of compartments for storing a particular bill or coin denomination, there is disclosed a method for checking out purchased merchandise items including the steps of displaying on the touch screen panel a receipt listing the items purchased together with the amount due, displaying on the panel a plurality of bill denominations which may be submitted by the customer for the purchase of the merchandise items and displaying on the touch screen panel a representation of the cash till together with the particular bill and coin denominations and the number of such denominations which are to be dispensed as the change due the customer in response to the submission of the particular bill denomination by the customer.