Linder - I have got my Beosound 5 working as an Airplay speaker via my iPad, iPhone and iTunes on my Mac. Just purchased the adapter at the link below then hooked it up to an Airport Express. Now I use the Airplay feature from link rooms so I can see and select my audio and then use the Beosound 5/Beomaster 5 when in the same room as the device.
The adapter is here:
http://www.amazon.co.uk/Behringer-UCA222-U-Control/dp/B0023BYDHK/ref=pd_rhf_p_t_3
Hope this helps.