For compact music playback, please consider one of the latest
generation of pocket MP3 players, such as from Rio, Samsung, Apple and
Creative Labs.  The memory card models can store one or two CD's worth
of music, and the models with hard drives can store many hundreds of
songs.  Browse Amazon.com for information.

There are many tiny amplifier cards available which can be used to
power speakers, such as from Radio Design Labs, http://www.rdlnet.com/

Regards,

Pete Woodworth
San Luis Obispo, CA