I have been working on an area lighting implementation in WebGL similar to this demo:
http://threejs.org/examples/webgldeferred_arealights.html
The above imp
it's been a while, but there is an article in gpu gems 5 that uses "the most important point" rather than the "nearest point" to approximate the illumination integral for area lights:
http://gpupro.blogspot.com/2014/03/gpu-pro-5-physically-based-area-lights.html