Based on this answer: Why add salt to potato water?
I always thought that water boiling was about getting the water to a specific temperature. You can't really get the water to a temperature past that point because as soon as it does it becomes vapor. You can stick it in a pressure cooker (again, the whole point from what I understand) to reach higher temperatures, but you'll never get past boiling. Also, it always takes longer to boil things at higher altitudes because of the reduced pressure and thus reduced vapor temperature of water.
But, I don't know everything (almost, but not quite). Is there something special about water that's vaporizing when it comes to cooking things? Could you really reduce the energy spent cooking something by lowering the vapor temperature of the fluid you're cooking in?