Synonymous with timeshifting TV programs, TiVo was the first company to get serious about non-computer use of HDs. Since then home AV use has developed so rapidly that now they are used in everywhere…car navigation systems to the latest cellphones and everything in between. Apple's iPod music player's HD can hold as many as 15,000 individual selections, presuming you have the time and energy to transfer that many tunes from around the globe.

Hard drives come in many sizes, capacities and versions. The recording medium is a metal or glass disk, coated and recordable on both sides. The platters can be as small as 20mm (0.8 inches) and as large as 130mm (the good old 5.1-inch). Most however are 65mm (2.5-inches) or smaller.

Most drives have multiple platters – 2,3,4. In 2003, it was estimated that about 360 million platters of all sizes were produced for about 250 million individual drives. This means the "average" drive contained 1.44 platters.

Much of the development work in disk drives over the past ten years has been in increasing the areal density and improving the magnetic heads that write and read the data. The areal density of a hard drive has jumped from 1GB/sq in five years ago to today's 100-150GB/sq in. Two orders of increase (100 times) is amazing and engineers say they can improve capacities 100 times or more in the next five its easy to see these little suckers aren't going away.

Cheap huge capacity drives will become the home network entertainment solution this coming year – wired or wireless. Think of a small enclosure sitting on top of your home theater with all of your music, photo albums, personal videos, archived TV series and movies stacked up waiting for you go pick and choose your favorite at will.