Pioneer beat its own record by announcing a 500GB Blu-Ray disk with 20 layers, beating its own 16 layer 400GB disc.

Now in case you are wondering what such a monstrous disc could be used for, there are a number of potential applications:

• HD backup - if reasonably priced per disc, a great backup medium
• HD collections - all the 007 movies in HD on one disc
• archival media for raw data from sensors

The prototypes apparently solved the "crosstalk" problem - where data from different layers interfered with the data from the selected layer.