In a recent Gmail blog post, a Google engineer has put together an app that helps deter you from sending out drunken emails.
http://gmailblog.blogspot.com/2008/10/new-in-labs-stop-sending-mail-you-later.html
Methinks it’s time for Google start making breathalyzers mandatory for all of their employees. If you really need an app like this (or consider developing one), you might want to consider you have other problems.