GeoPlayer v1.1 by M.Angelini (geoRAM not GEOS) is a very cool utility designed to take advantage of the speed and capacity of the geoRAM RAM expansion and the various clones.  With geoPlayer, you can play back .WAV files, SID music and Koala pictures.  The ability to upload these files to geoRAM is also built into the program.  There are a few limitations, such as only 10 Koala pics, and SIDs can only load to address $1000, but still a cool tool, and hopefully future versions will overcome these limitations.