What about satellite phones?
Q. My business travel takes me to many areas in America without cell phone coverage. What about satellite phones?
A. If your need was strictly personal you could study for your ham license, pass the test, and then connect with amateur radio equipment. But phone patches into the public telephone system are limited, and business communication is prohibited on the ham bands, so that option is out. Business radio, like what police or taxi dispatch services use, is local, complicated, and expensive to set up. A sat phone is probably the way to go.
I wrote about these people recently. I haven't done business with them but I can tell by their site that they are well organized. What's really nice is that you can rent first, to see if you like sat phones before you buy:
http://www.satphonestore.com (external link, no financial relation to privateline.com)
A refurbished GlobalStar sat phone, cheapest for calling in the Americas, and accessories may cost around $750, along with air time starting at $40 a month. But you will be able to communicate. You order over the web or call them and they ship the phone to you. Your employer may complain about the price but what is the cost of being out of touch and unable to do business? My first cellular phone in 1986, by the way, cost over a thousand dollars and my first monthly cellular bill was, dare I admit this?: $334! (I can still hear my old boss yelling at me.) One last thought, you need to be outdoors when you call, it's very tough to pick up a "bird" indoors. And here's a good URL on the technology:
http://www.space-technology.com/
projects/globalstar/
index.html#globalstar2 (external link)