23. The computer-readable medium of claim 20 , wherein the instructions that cause the determining whether the current version of the user interface comprises any textual items for which there is not already a corresponding audio file further comprise instructions that, when executed, cause the following to occur: retrieving a voice announcement identifier for a textual item under consideration; and consulting a database comprising a listing of voice announcement identifiers and corresponding entries indicating whether listed voice announcement identifiers are associated with audio files.
20. The computer-readable medium of claim 17 , further storing instructions that, when executed, cause the following to occur: periodically retrieving a current version of the user interface and determining whether the current version of the user interface comprises any textual items for which there is not already a corresponding audio file.