RealNetworks has announced the launch of a new iPod-compatible, DRM-free MP3 version of its Rhapsody music store. With a catalog of more than five million songs from all four major music labels as well as a number of independents, the Rhapsody music store will offer most albums for $9.99 and tracks for $0.99, and will offer full-length previews of songs, compared to the 30-second samples found on competing services such as iTunes and Amazon MP3. As…