I upgraded to Ubuntu 8.04 Hardy Heron over the weekend. The process was relatively painless, and some of the upgrades made little, but nice, improvements.
Finally, the UPNP media rendering functionality in Rhythmbox is working!
To set this up, you need to access the command line, and install the pyhton-coherence package:
<code>sudo apt-get install python-coherence</code>
Once installed, fire up Rhythmbox, and click on Edit > Plugins.
Once there, tick the box for DLNA/UPnP to enable UPnP.
Click Close and you should see a new shared tab on the left, which will list your network UPnP servers.
It’s somewhat limited in that it doesn’t present you with the various folder views that other media renderers will – but at least you can pick out music from network devices.