volume leveling -- This would be cool. I'm not sure how this is done, though. Would the software have to buffer the whole MP3, find the peak volume, then adjust to that? If so it probably isn't feasible. If however there is a way to do it on-the-fly then it might be possible.

Finding the peak volume and adjusting to it is called NORMALIZING, and all of the songs on almost all of your CD's were already normalized. So any routine that normalized the output would actually not make any change in the audio stream. The only way to do it is on-the-fly. A complete discussion of this topic can be found starting here and continuing down the page. You can't normalize, you must do dynamic range compression.

Fortunately, this dynamic range compression is already implemented in one of the available kernel hacks for the Rio Receiver. It is a port of Richard Lovejoy's "Voladj" code from the Car Player. I run it on my Rio Receiver right now. It works. It can be found elsewhere on this bulletin board as a kernel hack for the default software that comes with the receiver.

However, I wish that it would use different parameters than Richard's default ones, it currently pumps a bit too much for my tastes. Perhaps there will be a future version that can use the new default parameters that are found in the Car Player's Hijack kernel. HINT HINT!!!!!