> Blue ones are used, at least around my area, to decorate things.

Don't let the "blue LED" headline fool you. This discovery did not just enable blue LEDs but a whole range of nitride-based devices. This includes, but is not limited to:

* LEDs for a wide range of colours, including white LEDs for general lighting

* blue (and other colour) laser diodes (e.g. Blu-ray)

* solar cells (nitrides show good radiation resistance, making them of specific interest for space applications)

* high electron mobility transistors (power converters are a big application, but these are useful for a huge range of other applications too e.g. radar)

* potential for biosensors (it's non-toxic/biocompatible and can be functionalised)

* better UV emitters (and all that entails, e.g. water purification, or potentially lithography)

and more besides. It really is an enabling technology, though obviously there are alternatives for a lot of these applications too. Blue LEDs just started this all off.

The "white" LEDs you see in light bulbs in the store are actually blue.

How? Or is it a mix of Red, Blue and Green?

There are down-converting phosphors on the surface that convert a fraction of the blue light to other wavelengths to get close to white.

Is that the same method as fluorescent lighting?

Similar in principle.

Severe jaundice in newborns is treated with blue leds http://www.treehugger.com/clean-technology/leds-used-to-help...

Edit: LED lasers that enabled things like the Internet (Optical fibers often use DBF Lasers) were invented by Alferov and Kroemer that also shared the physics Nobel price in 2000.

Cool. It works because bilirubin oxidises under blue light into a form more soluble in water. en.wikipedia.org/wiki/Neonatal_jaundice#Treatment