If you can wait to upgrade, consider the Sony Xperia Ion, slated to join AT&T's LTE lineup later this year (no official date has been announced). I saw the Ion at its CES 2012 launch, and was impressed by its svelte design and high-end specs. The Ion includes a 4.6-inch display, an HDMI-out port, and a superthin design. It also has a 12-megapixel camera, which took great photos in our brief hands-on tests.
Sprint's LTE network hasn't launched yet, but that isn't stopping the carrier from releasing 4G LTE phones. The first of these, the LG Viper ($100 with a new two-year contract), is an environmentally friendly Android Gingerbread phone with a solid camera and an affordable price.
The phone's body is 50 percent recycled plastic, according to Sprint. Such Earth-friendly phones aren't generally stylish, but the Viper is an exception. A chrome border on the phone's edges nicely complements the piano-black face. The silver plastic backing has a "brushed" finish, giving it a sophisticated look. The Viper feels a little chunkier than other recent smartphones, measuring 4.59 by 2.44 inches and 0.46 inch thick, but it weighs a manageable 5 ounces.
The Viper might be easy on the wallet, but it's no slouch. Powered by a dual-core 1.2GHz Qualcomm Snapdragon S3 processor, the Viper feels snappy. In our tests, it ran three games--Osmos, Edge, and World of Goo--smoothly and without a glitch. One drawback: The Viper ships with the older Android 2.3 instead of the latest version of the OS, Android 4.0 (also known as Ice Cream Sandwich).
You don't have to be on Sprint to get the Apple iPhone 4S ($200 with a new two-year contract), as it's also available on AT&T and Verizon. But iPhone owners on Sprint can take advantage of the carrier's Unlimited Data plan, which offers unlimited data and text along with 450 voice minutes, for $70 a month, plus a $10-per-month "premium data add-on charge."
We love the iPhone 4S's premium design, upgraded camera, and faster processor. And like its predecessor, the iPhone 4, the 4S has a stunning 3.5-inch, 960-by-640-pixel IPS display. The iPhone 4S also introduced Siri, Apple's sometimes-helpful virtual assistant.