iPad 3G, is it only 3G Can the iPad 3G only use 3G and Wifi, or can it use Edge or 2G (the little blue dot on iphone)?
"3G + WiFi" is just a commercial tag line.

the 3G part stands for internet access throughout a mobile connection, usually using a SIM Card.

The full range of connections on a "3G" model can be found in the Technical Specifications of the product, in this case: