Recently, Google unveiled an exciting new feature to their email client: The Five Second Rule.
Gmail calls it the 'Undo Send' feature, which allows its users to take back an email if they catch it quick enough. We have all accidentally hit 'Reply All' instead of just 'Reply', sending an email to unwanted, and potentially embarrassing recipients. This problem is potentially fixed with this feature, which keep the email in your outbox for five seconds before the message begins to process.
Google Labs originally gave users the option of having the feature in June of 2008, but kept the feature quiet until it was stress tested by more and more users. The feature is now readily available to all Gmail users.
Google Labs offers hundreds of new and innovative features to its users, provided they understand that many of these features are remain in Beta form for additional testing. For more information, go to the Google Labs page.