Hi Novice,
Thanks for your enthousiasm, to be honest I left this project aside because I could not get any progress.
Using the arduino duemilanove, the rMP3 and an ethreshield, I managed to capture an icecast stream correctly but it could not copy it to the SD card (on the rMP3 board). If I redirect the stream to the USB serial port, it does work! I can listen to the radio, no problem. But as I said, the problem I have now is to copy this stream to the SD card on the fly and there is a problem with the rMP3 card with that, the write function fails 90% of the time to copy the data. Apart from that, the rMP3 module seems to work fine so I feel like I am close to completion...
Ok, I will try and make it work again, but that will probably need some changes in the rMP3 firmware too.