Yesterday I saw TV ads with the Sprint CEO promoting Sprint's new calling plan, which includes free calls to any mobile phone. I was tempted. I just checked the Sprint web site. This plan starts at $70! What the heck? That's because it requires the data plan with only 450 minutes to non-mobile phones. In other words, the same type of plan that I could get from ATT or Verizon. Since they have most of the mobile phones, it's not much of a plan.
It also appears to cover only outgoing calls, not incoming.