By Todd Bernhard
Those of us who adopted iPhones in the early days were rewarded with an AT&T unlimited data plan. Recently, AT&T told those customers that, while they could keep the plan, the price would go up by $5 per month. The wireless carrier has been encouraging users to move to a MobileShare plan, where all the data is pooled among multiple users, and it's not unlimited. Now AT&T has announced it will sell a new Unlimited Plan that includes unlimited data, talk, and text, but customers have to be a DIRECTV or AT&T U-Verse customer as well. The AT&T Unlimited Plan starts at $100 per month and goes up $40 for each additional smartphone, with the fourth smartphone free, so a family of four would pay $180 per month.