To Swamp Cool ... or not

Over dinner with friends last night the topic of swamp coolers (or evaporative coolers) came up. We are hearing different stories here in Palm Springs regarding whether or not it is an efficient way to save energy... and stay cool in the summer months when temperatures can reach 120 degrees.

One main advantage of a swamp cooler vs. air conditioning that I am drawn towards is the fact that you can leave windows open in the summer. Because you are using less energy and circulating a high rate of moisture, you can create a comfortable balance inside the house without being locked in. OR is that not correct?

Image by Nevit (Own work) [CC-BY-SA-3.0 (www.creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

On the down side, one of the issues of adding a swamp cooler to the central air system is the addition of yet another big box somewhere on or around the house.
Another thing to keep in mind is that if we build a well insulated, efficient home with new AC systems, the cost to keep cool should be manageable. The possibility of adding solar panels as source of electricity in the years to come might even play well with only focusing on AC units... is that not also a responsible approach?
We have time before making this decision, but this is a topic that is bound to come back.