An undo e-mail button for G-Mail?

I like this!!

By Mike Sachoff - Fri, 03/20/2009 - 09:20 4 comments
Google has added a new feature in Gmail Labs that allows users to retrieve email messages. A new Undo Send button will hold an email for five seconds after the user clicks send. Google says the purpose of this feature is to allow users to recall emails that were sent to the wrong person, have the wrong subject heading or are missing a file attachment.