This stuff is still way beyond the realm of being on consumer store shelves, but it definitely gives you an idea of what's out there, and where optical tech is headed. Heh... & I thought 300GB was a lot.

"The process is not reversible and produces write-once-read-many (WORM) media. Reversibility is being worked on and there is a generalised roadmap out to 5TB, still on CD-sized 120mm platters."