This is an excellent idea, please continue to explore it.
As my token contribution - Google App Engine allows storing and accessing several versions of the app (access through different subdomains). Perhaps one coudl use DNS to trick different users into seeing different app versions? Not quite what you wanted, but down the right path.
As my token contribution - Google App Engine allows storing and accessing several versions of the app (access through different subdomains). Perhaps one coudl use DNS to trick different users into seeing different app versions? Not quite what you wanted, but down the right path.