Squeezebox Media Server and AirPlay?

Ok. So the music is on the ultra, the control app is on the iphone, and you want to tell the ultra to stream directly to the squeezebox? Do we have that straight? If so, Airplay won't help - its an apple proprietary thing.

Though I don't have the squeezebox, it sounds to me like you need the Logitech server package installed on your ultra (NOT the OS6 version in superpoisson's dropbox) and the squeezebox iphone app on your phone. The squeezebox app appears to be a "fully featured squeezebox remote".

You should be able to get the ultra version of the server from http://www.mysqueezebox.com/download - "Netgear ReadyNAS Pro/Ultra/NVX" in the pulldown.

EDIT- I've tracked down your shairport plugin reference - there is a link here: http://blog.stuart.shelton.me/archives/762.
It appears to set up the linux box (ultra in this case) as an airplay client. Anything you play to it can be piped into the LMS server (also on the ultra). It looks interesting, but it does not seem to a a turnkey install.

I think to get it to do what you want, you'd need to
(a) install the itunes server on the ultra, and get it set up for airplay
(b) install LMS on the ultra
(c) install shairport, and set it up to pipe into the LMS server
(d) pair shairport with the the iphone apple remote app
(e) access the ultra's itune library from the iphone apple remote app, and select the shairport client as the player

This seems very complicated to set up, and if you are not an iTunes user now I don't know why you'd want to attempt it. It perhaps makes sense if you are running itunes on a Mac or PC, but it doesn't really fit what you are trying to do.