This is a flash mp3 player/widget. One can feed it a variable length playlist via XML. other than the audio files this player will progressively download and play, there are 5 files associated with this player:
1 this html file
2 AC_RunActiveContent.js
3 startingAgain.swf
4 mp3player.as
5 songs.xml

the source code (.fla and the above files) are available for download here

im not a big fan of how the JavaScript embeds the flash player... so check out this page for html layout control...