The Beijing Municipal Commission site. Responsible for selecting the architects of the Olympic Stadium. Therein are all the submitted designs.

From Wired New York I found this buried link which contains all the design submissions for the 2008 Beijing Olympic Stadium. Some are very western, some are resemble organic shapes you would see in nature and others look like UFOs. Seriously! Above is one of my favorite submissions. Granted the presentation is not very warm I am attracted to more organic forms that redirect rain water and are careful with where they direct light. [Link]