How to keep volume even?

rockbox, the opensource firmware support replaygain for ogg and flac. So do all the players supported by rockbox (my old iriver H140)

It’s sometimes the thing we could reproach to the mp3 playermanufacturer is to design a software just enough good to make the customer buy the product and not to try to do the best software to make the customer happy to use it on his day to day life.

But I understand the constraints of the manufacturer (big amount of money for few return over investment) even if I wonder if it will not be a good  investment because all the future mp3 players will benefit of this…

I’ve already ask for ReplayGain in the last firmware annoucement thread because I think it’s a must have feature.