Abstract: A novel method for using product identifiers includes capturing a product identifier identifying a product, selecting one of a plurality of queries, transmitting the product identifier and the selected query to a data provider, and receiving a response to the selected query from the data provider. The method is performed on a personal data device (e.g., a camera phone, PDA, tablet PC et.), which includes a network interface, a scanner operative to capture the product identifier, a user interface operative to receive the query selection, and an application program interface operative to associate the product identifier and the selected query, transmit the product identifier and the selected query to the data provider via the network interface, and to receive the response to the identifier and query from the data provider via the network interface.