Holographic storage
Holographic data storage has existed for 40 years, but is just coming to the commercial market and may reach the consumer market by 2007.
As opposed to the blue laser technology used both in Blu-ray and HD-DVD, holographic storage goes beyond recording the surface of the disc and records through the full depth of the medium.
Longmont, Colorado-based InPhase Technologies has formed an alliance with Hitachi Maxell to sell discs the size of a DVD that can store 300 GB of data. By comparison, Blu-ray discs will be able to hold 50 GB and HD-DVD discs will store about 30 GB. InPhase’s Tapestry holographic system can store more than 26 hours of broadcast-quality high-definition video.
While other technologies 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. So transfer rates are significantly higher than current optical storage devices.
As a result, the holographic discs also can read and write data at 10 times the speed of the DVDs currently in the market, or six times that of blue laser discs. [source]