But obviously, the phone in the "off" mode without the battery out still does not receive calls or notify you of incoming data.
So, just like a VCR or Computer, yes, the phone is not totally off, but still is in a sleep type state that warrants no audible or visual or vibrating notifications, until you "turn on" the device again. Then all missed calls, emails, texts etcetera are picked up by the device, and the notifications are enabled.
When you hold down the sleep/power button on the iPhone, it does the same. You get a screen that asks you to "slide to power off," and when you slide it, it goes through the motions and powers down. Is it totally off, no. It still needs a small amount of power to keep some or all of the buttons active, so that certain button pushes or combinations thereof, can re-awaken the device as needed.
Obviously, removing a battery from a device that has no backup battery will allow it to go into a power free state, but as I mentioned before, the only reason for doing that is to reboot the OS on the Blackberries. That can also be done through a key combination on the keyboard and it accomplishes the same result. Pulling the battery may just be a little better because it will allow the volatile memory to flush if the battery is left out for a short period of time.
But anyway, I see I have strayed from the general topic of this thread.