I was poking around the openembedded build environment when I ran across musicpd. Musicpd is a music playing daemon that can be controlled from a front end that connects to it over a network connection. GMPC and Glurp are two Gtk front ends to this daemon that as of 12/19/2005 build with no errors out of the OE dev tree. The memory requirements are impressively low, especially without a front end running (music continues to play when the front end is closed). MP3s and OGGs play fine (though OGGs take 60% - 80% CPU time!). Theoretically it should support AACs and FLACs but I haven't tried either. Glurp has an interface that I find is a nice match to the 640x480 resolution that my C1000 does. Anyways, down to the important part, how to make it work.
I attached the packages that I built. They're for the C1000 so they should work fine on the 5600 and up IIRC, but the interface seems to have a resolution of at least 640x480 in mind. If they depend on things not in the default GPE feeds, you might try looking in one of these two feeds:http://naismith.sakura.ne.jp/feed/
http://ewi546.ewi.utwente.nl/sfeed/
If the dependencies aren't there tell me what it asks for and I'll try and post that package as well. If it just complains about a minor version mismatch it's probably fine to -force-depends. Also attached is a sample configuration file, mpd.conf. I added an mpd user, added him to the audio group and chown'ed /dev/dsp and /dev/mixer to be root.audio. You could of course make them world writable if you wanted to. I didn't want log files to be written to flash, so I pointed thos at /var/log. Because of permissions the user mpd won't be able to write there by default. You can either make a /var/log/mpd subdirectory or do like I did and touch the two log files and chown them to mpd.mpd before starting mpd. GMPC comes with a desktop icon. Glurp does not. I included the one that I hacked up for Glurp. It uses the same icon that GMPC does because I couldn't be bothered to search for anything more suitable. You should change the music and playlist directories in mpd.conf to point someplace more suitable for your install.
Warning: Use these at your own risk! They are barely tested! All I can say is they work for me.
-John