Rhapsody for iPhone [free with subscription - iTunes link] has finally released an update to allow offline access to their music:
With a Rhapsody subscription, you can tap into over 9 million full-length songs, and download as much music as you want to your device. Create playlists for your commute, your workout or your flight - and download them instantly.
You can download and try Rhapsody for iPhone free for a week, and if you like what you hear, you can pony up $9.99 a month for a full subscription (which is locked to one iPhone).
It's US only, but we don't feel too bad for Europeans as Spotify [Free with subscription - iTunes link] revealed they were integrating Facebook Connect for the usual slew of new social interactivity, including sharing playlists, favorites, and likely the ability to mass shun songs and users who displease the collective (joking! A little!).
If you're a Rhapsody or Spotify user and you check out the updated functionality, let us know how it sounds to you!