If you have an original Motorola Xoom 3G kicking around and haven't sent it in for a free LTE radio upgrade, you might want to think about doing so soon. Verizon is ending the offer on March 31st, closing the book on what turned out to be a lengthy saga. You've been able to get the 4G upgrade since last September, but that followed a protracted rollout that was intended to have started "soon after" the tablet's initial February release. There doesn't seem to be any reason not to go for the upgrade if you've so far held out, though — it's free, you don't have to change data plans, and Verizon says that you'll only be without your device for about six business days.