Originally Posted by Nachtswerg
Same thing with the 650. Press and hold the red 'Cancel Call' button on the right of the treo. This will shut off the phone. Once the blinking light goes off, just press the red button again, quickly. This will turn off the treo.
I think all this really does is turn off the screen/lights. Essentially, put it in "standby" mode. I don't believe it's truly off.