The iPad 2 does not require cell phone carrier support to function.
It's main method of connectivity is wireless (WiFi).
As long as you have access to a wifi network, you may even have one at the house already, there is no need to the cell phone carrier.
There are two versions of the iPad, when it comes to cell phone carriers, one that works on the Verizon network and one that works on the AT&T network
Both can be activated from the iPad itself, using a wifi connection and are non-contractual.
The AT&T one runs for one month at a time and can be canceled at the end of each monthly period.
I assume Verizon does something similar.
Sam's offer both the versions that have 3G capabiltiy as well as just the wifi version.
I see the Sam's by my work has many iPad2's. If purchased there, I assume I would have to visit my cell phone carrier to set up a plan for internet access. Is this assumption correct?