Anyway, after playing a bit with the SoundMixer class, and adding basics Flint particles in the background (yeah, some default example), I ended up with a small flash visualizer and uploaded to YouTube.
I think it looks cool, plus I love the song, Deckers Theme by Dom & Roland.
The base of the code can be found at this old post from Mike Chambers. I advise you to play a bit with the code, you can get some really nice results. And by the way, it's never too late to learn new stuff ;)