I've just spent my weekend experiencing some sound handling capabilities of AS3 and have come out with this demo. This is a simple sound (wav, mp3) player features: common functions like play, pause, stop, fast-forward, rewind, seeker and other advanced functions like volume, pan, channel switch, especially the ID3 tags and spectrum info.
You can test the player by opening any online mp3 file. For e.g: http://www.fileden.com/files/2009/8/2/2530043/KhongConMuaThu.mp3 (Note: if the mp3 is hosted on a cross-domain site, that domain must have a crossdomain policy file so that this player can access ID3 tag and spectrum from the mp3s)
Download source code here.