clipped from: www.dataclinic.co.uk   

Background: Solid state storage devices such as the memory cards used in cameras / PDAs / mobile phones, and devices such as USB flash drives (also known as Memory Sticks) offer an extremely easy and portable way of holding data and transferring it between devices.

Some advantages of these solid state or 'flash' devices are:

superior portability
  • lower power consumption
  • no moving parts
    • Whilst disadvantages include:
    higher cost per Gb
    slower than conventional hard disks
    Typical USB memory stick / card / pen drive failure & data loss symptoms:
    The device will no longer be recognised by the computer when inserted
    The device will be recognised but appear empty
    The device will be recognised incorrectly &/or show the wrong storage capacity