In response to this article over here, yep, this one, I've found out you *can* power down your tethered Zune. You just have to take a different approach than the author was.

Basically all you do it disconnect your Zune from the synce device, press that Play/Stop combo button until the cows moo (or whatever expression he/she used), and then as soon as it shuts off *quickly* (quickly being a key word boys and girls) plug the synce cable back in.

I find that holding the Synce cable plug right in, but not all the way in the slot and then pushing it in completely as soon as I let go of the Power/Play/Pause/Stop button, won't cause it to start back up.

One thing I'm not sure about is whether the device will charge while it is powered down. My computer registers that a device has been plugged in (even when it's off), it just doesn't know what kind of device. I'll leave mine this way tonight and see if it will charge.

Also, this won't work while syncing (obviously). ;-)

Just thought someone might want to know.