I could have sworn my Pre let me turn the phone down even when it was in sleep mode (could be wrong, i'd have to double check). Would love to not have to push the wake button to turn down my ringer. I checked in settings, didn't see it there.
I don't know about turning the volume down, but if you hold the power button while the phone is sleeping, it will give you options to set to vibrate or silent without having to unlock.
http://img.tapatalk.com/d/14/01/16/ede6yqas.jpg
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