Flash drives place more storage capacity in the palm of your hand than the conventional hard drives of two decades ago bundled into 5.25-inch casework -- and at a fraction of the purchase price. These go-anywhere USB devices have become so inexpensive that companies use them as promotional giveaways. Flash drives can offer long life and convenient service, but maximizing their usefulness means paying attention to the special needs raised by their design and construction.

Physical Preservation

A flash drive looks reasonably sturdy, but it doesn't respond well to contamination from its environment. Its interior contains a small circuit board with a controller chip and a piece of NAND memory, a storage medium that retains data without the need for electrical power or battery backup. Exposure to moisture, excessive heat or cold can shorten the working life of your flash drive. Dust or lint that creeps in to the USB connector can interfere with its ability to make a proper connection to the USB port of your computer or other data-capable device. If the device includes a removable cap for its connector, keep it covered until you need to use it. Flash drives that slide or pivot out of an otherwise uncovered case may risk greater vulnerability to dirt and moisture than those with click-on covers.

Medium-Specific Warnings

The lifespan of a flash drive is measured in write cycles. The more you save files to one of these devices, the faster its memory cells wear out. For this reason, you can extend device life by saving files to your hard drive and copying them to flash storage, rather than using a flash drive like a regular storage medium and writing incremental document changes directly to it. The act of reading a document from flash memory doesn't contribute to wearing it, however. Because of the write-cycle wear factor, never defragment a flash drive. This drive optimization procedure reorganizes scattered bits of file data on the platters of a traditional hard drive so its read head can move shorter distances, making file access faster and more efficient. A flash drive uses no moving parts, and the act of defragmenting it constitutes an abundance of write cycles that contributes to premature wear.

In-Use Safety

If you use a Mac, you're accustomed to the idea of unmounting and ejecting removable media before you disconnect them physically from a data port. OS X displays a warning message if you remove a flash drive from a USB port before the OS releases it. On a Windows PC, the system tray includes a safe-removal icon to release these drives from use. Failing to follow these drive-safety procedures increases the risk of data corruption that can render all the files on your flash drive unreadable. Because of the portability of these devices, flash drives are an easy -- and sometimes unsafe -- method of transporting files casually from one computer to another. When you plug in a flash drive that someone else brings you, recognize the possibility that it may carry a malware infestation, and screen it before you allow it to read from or write to your system.

Other Considerations

One of flash drives' greatest advantages also can prompt one of their biggest risks. The compact size of the devices makes them easy to lose. Avoid using them for confidential files and never entrust them with your only copies of critical documents. Their pocket proportions also make them enticing playthings for pets and small children. A bath of saliva or a dental decoration doesn't contribute to the safety of your data files. If you carry a flash drive attached to your keychain, don't allow the weight of your keys to pull on the drive casing. The stress can cause the solder joints between the drive's USB connector and its circuit board to fail. Finally, when you select and buy flash drives, avoid "too-good-to-be-true" prices from unknown online vendors. These "bargains" typically yield counterfeit media: quality-control rejects, small drives fraudulently labeled as higher-capacity media and outright fakes with forged logos. If you purchase a flash drive that proves defective or deceptive in capacity or performance, return it for a refund -- if you bought it locally -- or contest the merchant's charge through an online sales venue or a credit card issuer.