I've got a few Audiotrons, and put some thought into this as well...

I think a better solution is to use the web browser on the iPronto, and the audiotron's http based API. My thought was, on my music server, also run Apache, and have a cgi script which displays my cover art, when you click on the cover, it will play the album for you on the desired audiotron.

Seems like it should be a pretty simple CGI script to write, at least for me, as my MP3's are all nicely tagged and sorted in a directory structure by artist/album...