All Electronics

Coolight

Cool Neon

E-Lite
EL panels, lamps, strips

EL wallpaper

EL Wire Cheap

GlowRings
Note warning message about radioactivity. Still - good if you need lighting on location for a self-powered installation.... (thanks Josh Goldberg)

High End Systems
makes a system to convert a projector into a motorized, computer (G4) controlled lighting and video system.

Lighting Academy
see especially 'Watt?'

LED

LEDs are already beginning to revolutionize lighting, with much lower power consumption and cost than incandescent. They can be computer-controlled to produce any color, and to change color dynamically. For example, it is fairly simple to have a user's computer interactions also control room or specialized lighting. See this article for details.

Arclinea
uses LED lighting to simulate dawn-to-dusk sunlight

Dallas Semiconductor Application Note
comprehensive introduction to LEDs

Dialight
makes those LED traffic signals, and related products

LED Center
Handy resource site

LED Effects

LSDiodes

Lumex

Luxeon
makes ultra-bright and efficient "lumleds"

Notes on LEDs

SloanLED
bendable plastic that resembles neon

Kevin Walker