Evaporative cooling. Most people know that a "swamp cooler" is 10x more efficient than A/C. The advantages to A/C is that it can easily be distributed throughout the house through the duct system and you don't need to crack open any windows or doors.
On the other hand Evaporative cooling or swamp coolers are much more simple to fix and just about anyone can fix one. They cost much, less. They brake more often than A/C does, but are much cheaper to fix than A/C.
Also Swamp Coolers only work in dry climates (generally rocky mountain states and west in the US), due to their nature of making water evaporate and absorb the heat from the air.
Anyone who TRULY cares about saving energy should be using a swamp cooler. But interestingly enough they are becoming less and less common, and more people are installing energy sucking Air Conditioners. These are probably the same people that sit at home in their nice A/C homes furiously blogging about people using too much energy and telling the world how THEY need to stop using so much. Then they claim they save energy because they don't flush the toilet as much or because they bought a "carbon credit".
