The part can be detached for lighter traveling. Sizes for portable hard drives are increasing as prices decrease. Many makers sell 5G and 10G drives, leading to descriptions of some mobile PCs as a LAN in a can. One maker reports that some organizations set up portable networks for doing audits in the field. Lithium ion is the favorite among travelers because of its long life and power availability.
Many users pack a spare for extended use in flight.
Mark A. Kellner is a free-lance technology writer in Marina del Rey, California.