Improvements to access control systems include the provision of a database in an access control device (i.e. key) and procedures assuring that the database, and a master database, are kept up to date. In the particular context of a real estate lockbox system, the keys are provided with a database detailing houses listed for sale in the local area. Updates to this personal database are conditioned on users first uploading to a master database data that their keys have collected in the course of their interactions with lockboxes. Additional features include the provision of statistical data on listing and agent data, a menu by which the access device solicits user feedback on a property just visited, and scheduling appointments to show certain listed properties. Radio communications are used in certain embodiments for updating the database and exchanging other data between the access devices (i.e. keys) and a clearinghouse.