Last year and this year I did some research on keeping cool w/o spending lots of energy on air conditioning. Okay, so I'm cheating a little because the SF Bay Area generally stays cool enough to not need air conditioning, but last summer had a couple unbearably hot weeks, and this summer looks like it might have more of the same.
Beating the heat without causing global warming points to a bunch of blog entries I've made on this idea.
I think a key thing is that we modern people are ignoring the techniques our ancestors spent millenia developing. How did they live without air conditioning? Well, okay, they probably complained about the heat, but they also built houses that used natural methods to create cooling, such as extremely thick walls (insulation), ventilation, etc.