I hope that we've made enough noise that you have noticed by now that next year, in Austin, is the 50th Design Automation Conference. An interesting article in Wired magazine points out that 50 years ago (actuallly on the 9th October) Nick Holonyak Jr and his team at GE invented the light-emitting diode. Wired has an interview with Holonyak. The first LEDs were red but it was clear even then that over time they would broaden to the whole spectrum and eventually you'd be able to make a white LED. Holonyak didn't expect it to take 50 years though!
But it has happened. In addition to being used for indicators, LEDs are now bright enough for traffic lights, for automotive lights, for flashlights and are starting to be used for general purpose lighting. As costs come down their power efficiency (and their more natural light compared with fluorescents) is expected to make them increasingly attractive for lighting. Plus, of course, the fact that we can build LED laser-diodes has become critical for fiber-optic communication. And, of course, your TV and your computer monitor may very well be LED-based.
In the chip world, there is discussion about on-chip optical interconnect since it has the potential to be much more power-efficient than current interconnect especially for clock distribution (which today can be as much of 30% of the power dissipated by a large SoC). A big advantage is that moving signals in metal cannot be done losslessly but with light it is possible to get very close.
Wired also has a gallery of uses of LEDs from the original calculators and watches (before LCDs had been perfected) through LED-based light up shoes for kids through to modern lighting.