SuperDisks and SuperDisk drives (sometimes referred to as LS-120 disks and drives) look nearly identical to a standard floppy disk and drive, and for good reason. SuperDisk drives are backwards compatible; not only can they read and write the super high-density 120MB SuperDisks, but they can also read and write the old 1.44MB floppy disks as well. One benefit from this is that you can completely replace your old floppy drive with a SuperDisk drive; you'll have the benefit of [what used to be] high-capacity storage, while still retaining the use of the "old standby" floppy disk, all in one convenient drive.
(Imation LS-120 SuperDisk)
While on the subject of benefits, there are two additional that I can think of. First, the SuperDisk drive is capable of reading and writing 1.44MB floppies FASTER than a regular floppy drive! The average speed is 2X faster for both reading and writing, however, some drives reached peak speeds of up to 5X faster for reading!
The second advantage is that SuperDisks are capable of data encryption! In order to accomplish this, you would have to buy specially marked SuperDisk media, and install a small application onto each computer that you wanted to have access to the encrypted data. While any SuperDisk can be used to store encrypted data, only the specially marked disks came with the necessary software to accomplish it.
As a side-note, a standard SuperDisk can be turned into one capable of encryption by copying the encryption files (folder) off of one of the specially marked disks, however, you are "forbidden" from doing this via the license agreement. I'm no lawyer, but I would believe that this license is now void (don't quote me on that!,) considering Imation no longer supports, manufactures, or warranties anything to do with SuperDisk technology as of 2003 (See second-to-last paragraph.)
SuperDisk drives use optical technology; the drive heads are laser guided. This is how the drive keeps track of the head's location on the surface of the disk, and allows it to properly read and write such a large amount of data in such a small space. Don't be confused, SuperDisks are still a MAGNETIC media, despite their use of laser technology. The laser is strictly used for location tracking.
(Panasonic LS-120 IDE) (Imation LS-120 USB)
SuperDisk drives are available as both internal (IDE, SCSI), and external (USB, Parallel, SCSI) devices. The drives were not only available for desktop PCs, they were also manufactured for many brands of older laptop computers, however, even modern laptops can benefit through the use a USB drive.
(Panasonic LS-240 SuperDisk Drive)
SuperDisks not only came in an LS-120 (120MB) version, but also in a VERY short-lived LS-240 (240MB) version. One REALLY COOL feature of the LS-240 drives is that they are capable of formating a standard 1.44MB floppy disk so that it is capable of holding 32MB! In order to accomplish this, the drive requires special software. The software was included with the drive, and is called, SuperWriter 32.
Unfortunately, the SuperDisk never really caught on in the mainstream market and Imation discontinued drive production in 2001. In 2003 Imation discontinued all products that were affiliated with the SuperDisk technology. Despite the fact that each disk has a "lifetime warranty," none of them are currently under warranty, as the "lifetime" of the SuperDisk officially ended in 2003.
With all that being said, the SuperDisk is still a viable option today. Support can be found in many other places around the 'net, and there is still a HUGE supply of drives and media out there. The technology, despite being dated, still has it's place, and most likely will for a number of years to come...