If u arnt grandfathered into the 30 unlimited plan and only have 2g of data like I did you can automatically be grandfathered in by getting the original iPhone( the one that came out in 2007) and putting that on ur account using iTunes, it will ask u if u want the $30 unlimited data plan, select it then once it's on and u have the old iPhone activated, reactivate your iPhone 4 and now you are grandfathered in!