Because of reception problems with my old service, I have to use AT&T's or Sprint's cell phone towers. I need two numbers. I would like to use my two unlocked cell phones with SIM cards that work on AT&T's or Sprint's network.

So who is offering the best price at this time? Is there a pay-as-you-talk or a monthly plan that really stands out? How about one with unlimited calling? I just want to get SIM chips, not other phones. Please try to include company or product names in your reply. Thanks for any tips!