Here's a feature Apple should implement: an option to boost high frequencies in MP3s before moving them to an iPod. This would be useful for people who listen in their car via a cassette adapter. The cassette adapter introduces high-frequency hiss into the signal. If you use your stereo's Dolby noise reduction, that cuts the high frequencies, which reduces the hiss, but also reduces the high frequencies of your music because the MP3s weren't encoded with Dolby in mind. If iTunes would boost high frequencies (or even officially Dolby process the music) in the files while copying them to the iPod, then they would work better with the noise reduction circuitry in the stereo, and thus the sound would be better. The noise reduction would remove the cassette hiss, but with little loss of high frequencies in the music due to the prior boost. A primitive, easy approach would be to just boost everything above 7khz by about 5 db. Alternately, the iPod (including the shuffle) could do on-the-fly high frequency boosting. Or perhaps for the Shuffle, since it lacks processing power, it could offer some analog treble boost in the amplifier circuitry, which could be turned on somehow.