I love seeing new engineering ideas for creating low-energy buildings and the "earth, wind, and fire" method by Dr Ben Bronsema shows promise. Basically it uses a combination of solar energy/heating, thermal air currents, and natural wind to keep buildings cool; the idea was created through studying termite mounds (which are exceptionally efficient at maintaining internal temperature). The Breeze Hotel in Amsterdam will hopefully open this year and be the first true test of the system.

Of related note, this article references similar engineering principles being used in Seattle (for quite a while now). The building there was built with lots of windows and a central, open atrium (think doughnut shape) so that air in the centre would heat up, rise, and pull cool air through the buildings as the convection current got going on warm days. Neat.