How to script Bluetooth on/off and Tethering on Snow Leopard

How to script Bluetooth on/off and Tethering on Snow Leopard

The Bluetooth / Tethering features in OSX are excellent. But they could be a little bit better. Is there a way to script (via AppleScript?) turning the bluetooth radio on and off, so that I could bind it into a key. No reason to drain battery while not tethered.