I think this has been alluded to in previous posts, but I'll ask the question specifically:

With the new pay music downloads now available (in particular Musicmatch and iTunes), does anyone know if either of these services allow converting a download into mp3/wma such that the Rio can play it? I guess that would involve transcoding from aac or wma9 into mp3 or wma? I suspect that the issue of digital rights management prevents us from "playing" in this arena?

regards,
-j

The only way I know to convert an iTunes downloaded file to mp3 is to burn it to a cd, then rip it to mp3.

I use "Easy CD-DA extractor 6" for ripping and converting. I find it very fast and has some great little tools for renaming tracks (changing upper to lower case, swapping the order of artist-title etc.). I haven't actually used it to convert .aac files, but it is certainly one of the options.
It is available as a fully functioning demo at www.poikosoft.com

M

I do the same thing with MusicMatch, download songs rip them to CD then leave that CD in and record from the CD in Music match. When recording the CD it usually even knows the songs to label them correctly.