A sales system is described that enables fast, efficient shopping by customers, and thereby increases sales and encourages customer loyalty, while simultaneously improving store management. An electronic device, which may be mobile or stationary, and which may belong or be assigned to (or accessed by) each customer, is used to access shopping information that might not otherwise be available to the customer during shopping. For example, a personal digital assistant or information kiosk may be used to provide specific product information and complete a sale thereof, or to provide suggested purchase lists and best routes through the store during shopping. The sales system is multi-modal, so that a plurality of input modalities (such as voice or auto-id techniques) are simultaneously available to the customer. Additionally, because it is multi-modal, the system can communicate with other store items, such as shelves or shopping carts, to gain (and integrate) information about customers and the products the customers are purchasing.