If you've ever experienced the dreaded Saving changes is not permitted dialog in SQL Management Studio, this tip is for you.
To disable the message, open the Tools -> Options menu and navigate to Designers -> Table and Database Designers:
From there uncheck the Prevent saving changes that require table re-creation checkbox. Hit the OK button and you'll be all set.
While this change might not be recommended if you're in a production environment, it's great to get rid of this block when you're developing and designing your databases.