Maybe it's not worth it for many people, but Ultra Mobile (T-Mobile's prepaid service) has a deal that is a low as $10 per month prepaid for 12 months, that provides, in addition to unltd calls, text and substantial 4G data in the US, text and data overseas at no cost, and even some free calls to a variety of countries. If you're traveling to the US and need a local cell provider, they're the best and lowest cost, with the overseas features. At $10 per month, and great functionality, it's easy to justify, as so may service providers I use require text confirmation frequently, CC's, banks, etc. in addition to eRewards.