The 3D smartphone battle is just beginning to heat up in the United States. Sprint was the first to market with the HTC EVO 3D, but the LG Optimus 3D (coming to the States as AT&T's LG Thrill 4G) is hot on its heels. The EVO 3D is powered by a 1.2 GHz dual-core Qualcomm Snapdragon CPU, 4.3-inch high-resolution qHD display, dual 5-megapixel cameras, a front-facing shooter, and Android 2.3 with HTC Sense 3.0. The Optimus 3D, on the other hand, sports  a 1 GHz dual-core TI OMAP CPU, 4.3-inch display, dual 5-megapixel cameras, front-facing shooter, and Android 2.2 with LG's custom UI.

They both have pros and cons, but as always, it's a dogfight - only one can win. Which smartphone will take home the gold medal? Part 2 of 2.