If you have no ac you could build this diy air conditioner and cool off this summer. I would say though and its (my own advice) if you also have no small children (due to water and electricity in close proximity to each other) this diy idea might give you some relief when it gets too hot.
He wrapped the fan with copper tubing and thin rigged it so cold water is pumped through the tubing so that the fan blows across the cold tubing thereby cooling the air. This is one of the neatest diy air conditioner I have seen so far. Check out the pictorial on Gajitz.