A US Cellular rep confirmed today that the carrier is now offering a new unlimited 4G LTE data plan. Customers within the company's LTE markets can now add unlimited 4G data for $40 per month -- only through January 31st of next year, though. If surfing the web on a smartphone isn't enough, you can add optional tethering for an additional $20, which requires a separate tiered hotspot data plan. Just in time for the holidays, this ample offering lines up with the carrier's recent LTE expansion and its plan to bring 4G access to 58 percent of its customers by the end of the year. In addition to this promotional data plan, US Cellular is offering a $100 instant rebate on select smartphones, including the Huawei Ascend Y and Samsung Galaxy S III. Not stopping there, anyone who purchases a smartphone or tablet can score a free Samsung SCH-LC11 hotspot. It's uncertain if this is truly unlimited data or the type that comes with a throttled cap. So, we'd caution you not to go on a Netflix and Pandora binge, as such activities could result in a nastygram from US Cellular for use beyond what the fine print allows.