The usual suspects...

The Bartlett - UCL faculty of the built environment
interactivearchitecture dot org - Hosted by Ruairi Glynn, unit 14
ruairiglynn
(n)eXt geenration - Toby Carr, unit 14
little orchid - Blog by Toby Neilson, unit 14
unnamable.org
Fred Guttfield

 
Others working with light...

Albers and Moholy Nagy Exhibition - Moholy's Light Space Modulator is at the Tate Modern. See blog post
James Turrell
Carpenter Lowings
Joost Van Santen
Olafur Eliasson
Julio Le Parc
Joachim Fleisher - Not a great link, best I could find. He's got a book: Joaquim Fleischer: About Light
Dan Flavin
Abelardo Morrell

 
Selected light projects
Levitated - Beautiful images of caustics through a vase
The Chapel of St Ignatius - Architect-Steven Holl
Jantar Mantar
 
Other useful sites

Glassian.org - Information on the history of glass prisms in building
Atmospheric Optics - Excellent site, if you like this you'll love this book: The Nature of Light and Colour in the Open Air
An interview with James Turrell - Titled 'Greeting the Light'
George Eastman House - Moholy Nagy Collection

 
Cybernetics Links

Paul Pangaro
Gordon Pask Archive at Pangaro.com
cyberneticians.com
Paskian Environments - Usman Haque and Paul Pangaro