Environment Toggle (local vs production)

I believe there should be an option to make changes based on whether the instance is local or production.

Mark Jaquith talks about it some in his blog:
http://markjaquith.wordpress.com/2011/06/24/wordpress-local-dev-tips/

The code I've written so far only hides the menu navigation in the WordPress admin so that staff aren't directed to make live changes to files.  This could be expanded to help implement more good practices for local/production environment differences.  It assumes production by default so it doesn't affect people who don't use it.