AT&T and Verizon bid farewell to unlimited data plans long ago, but other carriers have thus far kept the desirable option alive — albeit just barely. US Cellular is the latest to join in, giving customers with an LTE-enabled device the chance to switch to a $40 unlimited data plan during the holiday season. Naturally the special rate comes in addition to your regular voice/text package, and you'll also need to reside in one of US Cellular's LTE markets to take advantage. But if you meet that criteria, you'll be able to sign up for a maximum of 24 months of unlimited data. US Cellular is placing an emphasis on that two-year limit, saying it will help customers find an appropriate tiered plan once the unlimited agreement lapses. Unlimited tethering will be an optional add-on for $20.

Though US Cellular's offer may strike you as a promotional stunt — particularly thanks to that hard cutoff — unlimited data plans (particularly with LTE) remain rare among the major US carriers. The only way to maintain such a setup with Verizon is to buy all future handsets at their unsubsidized, full retail cost. But Sprint, MetroPCS, and now US Cellular are keeping the concept of unlimited data from disappearing, with T-Mobile continuing to serve up unlimited plans to 3G users. It could prove to be a powerful draw to consumers as these companies fight to pull customers away from the much larger AT&T and Verizon. US Cellular has yet to specify when it plans to stop accepting new signups for the unlimited plan.