For the lazy home networking addicts (like me) out there, there are times when you hate to have to move over to your Rhythmbox machine to turn down the volume or to skip a song, especially when that machine is one room far away from where you are. :P
There are also times when you might want to change the music from the comforts of your cozy bed.
Whatever be your efficiency / productivity / "laziness" need, here is one good remote interface to remotely control your Rhythmbox player:
Rhythmote - a web interface plugin for Rhythmbox that does what it's named to do.