Use of the Radio class requires that authenticate as described at 
http://www.last.fm/api. Also you will need a api_key that is authorised for
radio playback.

If you want to handle media playback yourself, you can simply use the Tuner
object, and play the mp3 urls you get back.

If you want a complete solution, create a Radio object, and pass it a 
Phonon::AudioOutput.

<max@last.fm>
