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.
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. 22. 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: transmitting a request for an audio file header corresponding to a textual item under consideration; receiving the audio file header; and determining whether a size indicated in the audio file header is greater than a predetermined minimum size value.