AT&T used to offer unlimited data but killed off its unlimited plans in 2010. Verizon scrapped its unlimited data plans in July.
Sprint is the only carrier that still offers an unlimited data plan at a cost of $79.99 a month.
T-Mobile's 500-minute, unlimited text and unlimited Web data plan is available for $79.99 a month. However, the company slows down data speeds once a subscriber consumes more than 2GB of data in one month.
Apple still hasn't unveiled its fifth-generation iPhone, although there has been much speculation on the web about possible features and specs of the new device. Last week, Germany's Deutsche Telekom started taking pre-orders for the new iPhone model.