Competition among US cellular carriers is about to get a bit fiercer with a fresh national network that will actively encourage using your phone rather than setting hard limits. Newcomer (and MVNO on Sprint's network) Voyager Mobile is teasing a "frequent talker program" that will give all kinds of perks for the more talkative among us: call your Aunt Ruth a lot and you'll get phone upgrades, free months of service and smaller nice-to-haves like air mileage and gift cards. That's helped by Voyager starting off at $19 a month for unlimited voice, although picking a smartphone in t
