Ultimate Radio
 

I've noticed, using XoloX, that I can download tunes much faster than I can listen to them. This opens up all sorts of opportunities, combined with the file ranking system.

Suppose the program constantly scans for mp3 files, checking the genre in the ID3 tag against your list of choices (ie Rock, Country, etc). The highest-ranked files that you don't have get downloaded periodically, maybe every two hours or something. Your playlist would never grow stale!

It'd be really darned cool if winamp could constantly update its playlist automatically to add your new songs. I'm sure there could be several creative solutions to this, but I can't think of any just yet.

Another issue is space--maybe it could clean up after itself periodically, after you've had a chance to 'archive' the files to your main mp3 directory.