Everyone should be familiar with the most common forms of optical storage, such as CDs and DVDs. CDs can hold 650-700MB of data, while DVDs can hold up to about 8.5GB of data (on dual-layer disks, single-layer disk only hold about half that amount of storage).
Although, have you thought about the next generation of optical storage? You probably have heard about the high-definition (HD) format wars between Blu-Ray (supported by Sony, Matsushita and others), and HD-DVD (supported by Toshiba and NEC). The way that these new HD drives work is by using short-wavelength blue-violet lasers to increase data density on the medium. Blu-Ray disks can hold about 50GB of data, and HD-DVD disk can hold about 30GB (and up to 45GB on triple layer disk)
If that isn't enough storage for you, have you heard about Holographic storage which stores data as a 3D image? These new Holographic drives promise huge amounts of storage and very fast access times. InPhase Technologies announced they will ship a holographic drive next year that will store 300GB of data on a disc about the size of a CD, with access times of less than 200 milliseconds. By 2009, InPhase wants to ship a drive that can store 1.6TB of capacity per disk. The major problem with this technology is finding material sensitive and stable enough to store a holographic image.