OP, I'm a little confused about the "Free 3G wireless connectivity" for the $70 model. I know about connecting via WiFi, but have never used 3G. Does it matter if the provider is ATT using CDMA service, or T-Mobile using GSM service. I assume that the Kindle is assigned a unique calling number that can only connect with an Amazon server. How does the service provider get paid--do they bill Amazon? Thanks.
They use AT&T in the USA and various other GSM providers in other countries. The provider bills Amazon.
The 3G keyboard version includes basic email and browser functionality.