If the Treo is your preferred device for all occassions this certainly seems like a great add. PocketTunes is a killer app for the device and iTunes integration is just solid.
The newly released version 1.3 of Mass Storage Synchronizer, a free iTunes add-on by Tea Vui Huang, lets you sync iTunes to your Treo 600 or 650. Just use either RealPlayer for Palm or Pocket Tunes to play the synced music.
GearBits: iTunes On Your Treo? No Problem.
