So one can preorder with say Vodaphone (I assume by internet) and the "chip" is waiting at the counter in Joberg Airport when you arrive, you swap out your chip for theirs and wha-la it's just like having your own phone here in the states? If that's how it works- COOL NOW what about making and receiving calls from the USA?
In researching I find a company called "Cellomobil" and it looks like they hook you up with a cellphone that they ship to you before you leave and you mail it back when you return. It looks cheaper than standard one of renting one in the airport at Joberg and most countries are available.
I'm going to presume also that smart phones can get 3G (?) and/or internet in lots of places around SA and Namib?
Also, as I'm not a phone junkie (that seems redundant right now), I didn't pay attention at the airport in Windhoek when I was just there a few months ago to see if phone rental was available there. My PH (Jamy Traut) used his phone a lot while traveling so it looks like service is probably good in that country (my seminar focuses on SA and Namibia ).
I'm learning fast with your help guys, Thanks BUT I AM KICKING AND SCREAMING

Bring back dial phones!!!!
And to think I was rated as Capt in a Boeing 757 at one time with 356 computers on board to make it fly!
A short story. I once had a crew in which 2 of the stews (opps sorry, not PC) 2 of the FAs where talking to each other on their cell phones (while at the gate) from front galley to rear gally and texting some one else each on another device at the same time. Gadds!
Things that I don't care about (like phones) I guess, are lifelines to others. What ever happened to the CB radio craze? That was fun.
Just found a cell phone coverage map of southern Africa that I dropped into a PP slide.