So I found this sound annoying and was surprised that it can't be disabled manually via the settings.
Anyways, here you go (not I tried editing the other strings in that directory and no effect--this is the only one that works):
To disable the shutter sound on the Treo 700wx's camera use a registry editor and go to:
HKLM\System\Pictures\Camera\OEM\SoundFile
Under "String" it should say
\Windows\ShutterSound312.wav
Simply edit out this line and leave the string empty.
Exit the registry and do not soft reset for at least a couple of minutes to let the change write to ROM.
No soft reset is needed for change to occur.
Now, whenever you take a picture there will be no sound.