You have your Iomega Zip and Jaz drives, your Syquest SparQ drive and, of course, your floppy drives, but in my opinion if you need a high-capacity removable storage medium and drive, the best choice is the recordable CD.
All these drives work something like floppies: when you fill one up, you take it out and put another in.
All these drives have substantially more capacity than the 1.4 megabytes of a floppy disk, but the disks they use are also more expensive, between $50 and $800 each.
On the other hand, CDs can be had for as little as $6 for a whopping 650 megabytes of storage space. The data on the discs cannot be erased, which is great for archiving. Most importantly, everyone has a CD-Rom drive.
Send a courier over to a client's office with files on a Zip or Jaz or magneto-optical disk and you may find that they do not have the drive they need to read your disk.
When you think about the comparatively small drives found on most laptop computers and the convenience with which you can carry a whole pile of CDs, Hewlett-Packard's portable M820e CD-R is a sensible way to expand your storage space.
The drive connects via a Type I PC card and is about the size of a bulky portable CD player. Usually you expect portable equipment to be a step or two behind that which you can buy for a desktop machine, but with 20X read and 4X write, the HP is fairly average speed for a CD-RW.