1. A method, comprising: ordering records of airline flights based on a combination of factors including age of cached flight availability information associated with at least a portion of the records and time-to-departure; querying one or more airline information sources for flight availability information corresponding to the records in accordance with the ordering; and caching flight availability information received from the one or more airline information sources; wherein the ordering, the querying, and the caching are performed within a suitably programmed computer system.