Basically, you just construct and RSS feed with parameters for your own user names/IDs. For example, here is mine:
Note that most parameters are your username, but both Rhapsody and Imeem IDs are harder to come by. Your Rhapsody ID is found in your My Rhapsody RSS feed URLs. Your Imeem account number is even harder to find, but I'm working on trying to find a better way to get to it.
If you can then take that feed and do anything you want with it.... embed in a widget on your blog, feed it to Streampad or Yahoo Music Player, subscribe to it as a podcast, dump it into your lifestream, feed it into your Twitter account, etc.
One thing I was thinking about is playing around with "rooms" on FriendFeed to see how this would look as a collaborative "station". Other ideas? I'd love to hear them.
UPDATE: I found some issues with the way I was dealing with and rationalizing dates across all of the services. This needs more work and until it is fixed you may see stuff jumping around in time like the castaways on "Lost".