California-based HPV Technologies recently demonstrated a "magnetic acoustic device" or MAD that can broadcast a targeted beam of sound for a more than mile.
In addition to features available for the Advanced Series, it features a five-inch multi-touch glass screen in a brushed-metal housing as well as a powered magnetic mount that automatically snaps in once the user holds the device close.
Backup and archiving remain the biggest applications for digital magnetic tape although it is also used as a physical data transport device (as the old saying goes, you can ship more data on tape in a delivery truck over a shorter time than you can send electronically).
Aside from magnetic tape (which generally has a slower time to access information) there is no more cost effective storage device to keep all this content on than HDDs.