Blu-ray may be the next big thing, but the laser diodes are in short supply.
I would hope that most people would know what a laser is. For those who are not familiar, laser stands for 'Light Amplification by Stimulated Emission of Radiation'. Laser themselves were first conceived of back in the 1950's and first demonstrated in the 1960's. Now, they are everywhere. But the blue ones, they're really hard to find.