The mobile version of Sncf.com, the French rail operator's website, was recently awarded a prize for the innovation of the company's mobile strategy (see here for an article in French about that).
On sncf.mobi, you'll of course find all the necessary practical information about train schedules and traffic, but also some entertainment content. And as far as music is concerned, jamendo is the sole source! Every month, a playlist “evocative of travels and relaxation” is available for the users of the site. You can check out the first four editions here.