Spray it with a hose. Wash, rinse repeat.
You have suggested the safest thing to do, although MOST folks won't do it. The repeat part is unnecessary but the safest way of removing ALL dust from a car is to PROPERLY (as in 2-bucket), wash it.
I use a blow gun for light dust. (have an air compressor in the carport area)
Again, an excellent suggestion! This is what I usually do using my Air Force Master Blaster, or I just leave it dusty (air compressors can have water or dirt in the bottom of the tank so I avoid them). Then you went to hell and a hand basket with the rest of your advice but at least you acknowledged the error of your ways. Kudos to you for that.
The Junkman would be digusted with my car. -or be able to charge me a lot of money to fix it.
I wouldn't charge you a dime. I would just fix ONE quarterpanel and let it torture you every time you looked at the rest of the car.
Here's the deal OP. There's a difference between DUST and DIRT. Dust can be removed by blowing it off the car. It can also be removed by using a California Duster, but ONLY if you use it CORRECTLY. ANY quick detailer can be used to assist in the dust removal process if used at the PROPER TIME. Dirt on the other hand MUST BE WASHED off the car. Dirt will not move when you blow it. Dirt cannot be removed with a CA Duster. Dirt cannot be removed with a quick detailer. I say CANNOT to all these things if you are trying to keep your paint perfect. Of course you are welcome to do it the wrong way, the way that a lot of people do, just be ready to see some swirled up paint in the future. It usually never happens immediately, it takes time. But when the day arrives that you notice it, it looks like crap. Don't be that guy!
Here are 4 videos for you to watch. The whole time that you are watching them, I want you to think about one thing. Think about how much common sense and logic that I am using in the advice that I am giving. I am not using any rocket science whatsoever. If you follow me, everything you hear and see me do will completely be obvious to you. As for a quick detailer to use, don't get caught up in the hyped up advertising that you see from sellers of detailing products. After all, they have a horse in the race. So find whatever quick detailer you like to use, get yourself a CA Duster (the one with the wooden handle is the one I like), and watch the following videos. You will be amazed at the amount of logic that is in them. Especially since your car sits in a driveway.
Your learning curve starts here.
http://www.youtube.com/watch?v=BDevg-0x0jI
http://www.youtube.com/watch?v=oqdjRwsXoOM
http://www.youtube.com/watch?v=8gVU4C_6wOE
http://www.youtube.com/watch?v=3PeMi05kZyY