The deal with Verizon is that you can tether a laptop or other device to an iPad. Since you cannot have a cell phone without a data plan, the only thing this really works with is laptops/netbooks. The VErizon smart phones will not allow tethering for free. I also doubt that your Blackberry sim will fit an iPad without modification, but even so, it would be against the Verizon rules and could cost you your data plan. Most people use about 2-4 Gb of data per month. Non-promotional rates are better for AT&T in that range, but when you go to 5 Gb, they both charge the same.