Amazon has been spending a lot of time and money trying to catch up to Netflix in the subscription-video race. So far, not much luck: Many more people seem to be watching video via Reed Hastings’s service. But now Jeff Bezos has something new: Offline viewing. Amazon’s new line of Kindle Fire HDX tablets will let Prime Instant Video users* download some movies and TV shows to their devices, for free, for up to 30 days, so they can watch without an Internet connection. Once they start watching a particular title, they’ll have 48 hours to finish. That’s a feature no other U.S. subscription-streaming service currently offers. And it might prove very handy for travelers, or anyone else who wants to watch something on a laptop or tablet but doesn’t have access to good broadband. Amazon says it would like to make the feature available for all of its Prime Instant shows and movies.