It seems that, from Google Cloud Console there is no way to delete a project.
Note: As of 2013-09-19 this is no longer an issue because Google had fixed
It's July 2018, none of the above works. Here is what I spotted and successfully deleted un-needed projects.
https://cloud.google.com/go/getting-started/delete-tutorial-resources
You need to delete all the unwanted project(s) else will be billed regardless.