I'm guessing it's not frowned upon to discuss this any longer, given the deluge of topics regarding the subject in recent days/weeks. Anyway, I've just purchased an Audiax II FM transmitter to play my Sony NW-HD3 through the car stereo. The unit was recommended to be used, in order to achieve best sound quality and clarity, on 88.1 FM frequency. Unfortunately, a local station assumes 88.6 as its home and slight interference can be encountered from 88.0-88.9. This got me thinking, is there an image which covers the frequencies used by radio stations so I can allot the Audiax to the largest 'empty' frequency on the radio spectrum?