We're currently running in the mid-90's with dewpoints in 80's. "Swamp coolers" just don't work well in this climate, so I don't know how useful this will be to us.
Wikipedia doesn't do the principle justice. A swamp cooler is essentially a big fiber mesh (which can look and feel similar to cardboard but holds up when it gets wet). This mesh is constantly sprayed with jets of water to keep it wet -- damp isn't enough. A big fan, bigger than a typical air conditioner, forces air through this mesh and pushes it into the house. Each room that needs to be cooled needs to vent air out, typically into the attic and out into the outside. The more air you move through this mesh, the cooler the house, so it's typical that the air volume is much higher than an air conditioner.
The humid air introduced into the house is essentially at dew point (if it's lower than dew point, the mesh / jets aren't doing their job forcing the water into the air), so the house will likely be warmer than that, making a few assumptions about the conditions outside. Now, if you had this pre-drier in Alabama, dropping the dew point to 40 or 50, you'd be able to cool the air 20 or so degrees -- about what your air conditioner does.
By the way, I grew up in Phoenix. Instead of the $400/month power bills from running the air conditioners, my parents opted to run swamp coolers. The water bill regularly got above $100/month, but the electric bill didn't. Financially, it was a good trade-off. I'm told there are health benefits from breathing more humid air instead of dry desert air, and the air was constantly being refreshed from the outside, so there certainly weren't any toxic house concerns that people in some areas of the country have. On the flip side, there's the monsoon season, which is typically the whole month of August; the dew point rises to the point where swamp coolers just don't cool much. Several of my Magic: The Gathering cards (mostly Revised aka 3rd Edition) felt like they had a powdery coating on them. I assume this is mold. If it was on my cards, I'm certain it was on countless other surfaces we just never touched enough.