Abstract: A portable data terminal device configured as a personal shopping assistant (PSA) may display information about product locations in a store, product features, and alternative product recommendations upon request by a customer visiting the store's physical location. The PSA may detect and identify items placed into a shopping container, maintain an inventory of items selected for purchase, and communicate the inventory to a check-out station for rapid and convenient check-out and payment by the customer before leaving the store. The PSA may detect its location in a store and may activate an alarm when the PSA is moved outside a geofence boundary.