AT&T has just published extended details of its new unlimited mobile-to-mobile calling plans, first revealed on Wednesday. Individual subscribers must be on a Nation or Unity plan worth at least $40 a month in order to qualify, and pay an extra $20 a month to turn on unlimited mobile-to-mobile. Eligible family plans include FamilyTalk and FamilyTalk Unity packages worth $70+ a month, for which adding the new feature costs $30.
