Twt.fm allows you to:
type in an artist, track, your twitter username, and click the preview button twt.fm will then generate a track page for you using your twitter page design and you’ll be able to tweet it to your followers.
if we can’t find a stream, you may also provide an mp3 link or youtube link to your audio
I tested the application by putting in my Twitter username, an artist and a track. It pulled my profile background from Twitter and put a player in place while I watched it reach back to Rhapsody to pull the stream. Then it allowed me to tweet it. Simple as can be.