Phew this was a pain because I could not find the binaries for mt-daapd and arm so i had to scour the web for information and amazingly got it working, heres how...
first get some required files
apt-get install build-essential debhelper fakeroot libgdbm-dev libid3tag0-dev
then get the latest copy of the source - this was the first of my problems, as i needed 0.2.4 as its compatible with the latst version of itunes .. for reasons i'll illuminate later get the following two versions.
tar zxvf mt-daapd-0.2.3.tar.gz ; tar zxvf mt-daapd-0.2.4.tar.gz
now the thing that screwed me up for a day, is that the changelog file in the latest release (0.2.4) was blowing up the dpkg-build process (it had wrong case, and contained some incompatible chars) so copy the version from 3 over 4. i added an extra made up entry for v4, not sure if its needed, but it didnt break anything
cp mt-daapd-0.2.3/debian/changelog mt-daapd-0.2.4/debian
now configure - will take a few minutes
then move back a dir and install
dpkg -i mt-daapd_0.2.4-1_arm.deb
now its all done, just edit the '/etc/mt-daapd.conf' file, point to your mp3s, you might need to chmod all the files in your mp3 dir to enable mt-daapd to see them 'chmod o+r -R /media/hd/Music/'. Now start the server '/etc/init.d/mt-daapd start' open itunes on your PC and bask in the glory that is music served up to your network via ITunes.
I found some useful urls along the way
0.2.3 mt-daapd install notes
mt-daapd config notes