Now THERE's an idea! So long as it can be controlled so that you don't blow so much as to fill your bladder with slobbery 'ol mouth germs (not to mention sloshy air bubbles). I'll surely try this.

On your other point, if it's so cold that water is freezing in my hydration bladder ... well, you won't find ME out hiking! I'm getting too old for that. More likely you'll find me curled up with a cup of tea in front of some episode of Lost on the TV. Yes, I know it's not an accurate survival show (Sayid washing his hair in the group water supply? Yeuch!) But still a fun show to watch anyway.