I have been trying some of his tips, plus some of my own ideas, and thought I'd share them here.
The results have been very successful, and at my house we now run our air conditioner for only brief periods of time throughout the day while the other tenants in our unit blast theirs almost nonstop.
The most interesting thing I discovered is just how arbitrary the standard 72 degrees F is. I am convinced that this temperature is based on wearing a business suit, which people almost never wear in their own homes in the summer. The truth is that there is no ideal temperature.
These ways to stay cool fit into three categories: Lowering the temperature of your house, lowering your body temperature, and changing your perception so that the heat doesn't bother you so much. Not all of these steps are practical for everyone, but if you can find one or two that you can turn into habit, it can make a difference in comfort and/or in energy consumption.
In addition, I have listed some bonus "green" benefits on each step where they apply.
Step 1: Get naked!
I know this isn't for everyone, but its amazing how much more comfortable 80 degrees Fahrenheit feels if you're shirtless.
If you live on your own then this is no problem.
If you live with close friends or family, then wearing just your underwear is probably not a big deal either.
If you live with roommates, you can wear lighter-weight clothing like shorts, tank tops, etc. Even going barefoot helps your body eliminate heat more effectively.
In any case, you can probably wear as little clothing as you like at nighttime while you're in bed. If it feels strange at first, give it a few nights and see if you don't get used to it. While you're at it, get rid of your blanket and just sleep under a top sheet.
Wear fabrics like jersey cotton, nylon mesh or linen which don't hold onto heat.
BONUS: You will end up doing less laundry.
BONUS: Your clothes will last longer since you are spending less time wearing them and not washing them as often.
BONUS: Being naked is fun.