LTE device momentum is accelerating. Although it is difficult to quantify how many LTE device models have been sold so far, operators certainly are working hard to get consumers to migrate to LTE devices and LTE networks. According to research from the NPD Group, sales of 4G smartphones reached 22 percent of all U.S. smartphone sales in the second quarter (NPD considers smartphones to be 4G if they support LTE, WiMAX or HSPA+ with downlink speeds of 14 Mbps or greater.) There are a handful of devices in the market and even more in the pipeline. Although the first LTE devices for Verizon and AT&T were USB modems, smartphones and tablets provide carriers with a greater chance to differentiate their LTE networks. Here is a rundown of some of the most high-profile LTE smartphones and tablets currently available from U.S. carriers. Click here to see the hottest LTE smartphones and tablets available today.