The solution turned out to be quite simple. Remove the WRITE access to the default project directory for my development user account. Now when I go to save, I am presented by the following dialog:

This gives me one last warning that the project doesn't yet have a home...I can now decide where to place it and what it will be called. Actually, I can't even RUN the application until it has a home...
Granted this means that there will probably be another directory with a hundred ProjectN programs... but I'll know I put them there on purpose.