Technology makes geeks happy - simply because it exists.

The first holographic storage systems, storing up to 300GB on a single disc, will go on sale towards the end of 2006.

InPhase Technologies and Hitachi are jointly developing the technology, which uses laser light interference to store data in a light-sensitive crystal material.

The technique could be developed to store up to 1.6 Terabytes on each disc - more than 300 times the capacity of a conventional DVD - and offer read and write speeds of up to 120Mbits/sec.

Unlike other technologies, that record one data bit at a time, holography allows a million bits of data to be written and read in parallel with a single flash of light, This enables transfer rates significantly higher than current optical storage devices.

The high transfer speed enables the playback of broadcast-quality HDTV content, of which 26 hours can be stored on a single disc.

Holographic storage works by splitting light from a single laser beam into two: the signal beam to carry the data and the reference beam. The hologram is formed where these two beams intersect causing a chemical reaction in the recording medium. By varying the reference beam angle, wavelength, or media position many different holograms can be recorded in the same volume of material.