I think the reason that hard drives fail is because the magnetic storage is a spinning disk like a record. The pickup head moves across as it rotates. There is a small gap which is caused by the pickup head 'floating' (not the correct word really) on air just above the disc surface. Lower pressure equals lower 'lift' for the pickup head and if it touches the surface it damages it(which is what can happen if you drop a hard disk).
Solid state memory such as MP3 players and the Apple Nano have no moving parts and are better.
Last edited by Zulu Alpha; 15th December 2006 at 15:14.