I actually have an external working with music that works
its an external powered hdd, only issue ive seen so far is when the power is turned off, the power inverter goes into a shock and you have to power cycle it when you start up again.
Also, you have to unplug/plug in the hdd to be recognized by the usb drivers :/ kinda gay...
I have an external usb powered drive in my possession, i tried attaching it, but I dont think it was enough power because wince didnt recognize it and the hdd was making noises that are usually made when there is low power