Movie rentals are available for up to 30 days after payment--until you hit Play, that is. Once you start watching a movie, it will only be available for 24 hours from the moment you started. View rentals on your desktop or laptop, or transfer them to your iPhone or iPod. Sadly, owners of older video-capable iPods are out of luck: Movie rentals are only compatible with the iPod Classic, the iPod Touch, and the third-gen iPod Nano.
Photo credit: Apple