AT&T is one of the two largest wireless carriers in the United States, providing cell phone service to over 95 million subscribers across all 50 states. AT&T uses GSM technology --- most of the company's phones will work seamlessly on wireless networks in dozens of countries around the world. The company's unique Rollover feature lets subscribers bank their unused minutes for use in a subsequent month. On this page, compare current AT&T cell phones. Click the Buy button for full offer details.