Architecture Week Design Community
This architecture and design web portal provides forums for public communication on world architecture, sustainable design, 3D design and 3D computer graphics.
http://www.designcommunity.com/

ArchSociety
A global online forum and resource library for architects and architecture students.
http://www.archsociety.com

i-Think
An online community for the property, architecture and construction sectors, dedicated to professional networking, stimulating debate on sustainability in the built environment and showcasing best practice.
http://www.i-think.com