Google lets Gmail users hit panic button with Undo Send tool

Wish you hadn't sent that Gmail e-mail? If you're quick, you can 'unsend' it

Ever have one of those "oops" moments?

You know, when you hit "send" on that off-color e-mail and suddenly realize that you sent it to your boss instead of your friend. Or when you accidentally "reply to all" when you're joking about how useless an e-mail group is.

Now you might be able to take it back with a feature Google Inc. has added to its Gmail service. Google's Gmail Labs has created an Undo Send button designed to hold e-mails for five seconds -- but only five seconds -- so the sender can pull them back if necessary.

More: http://www.computerworld.com/action/article.do?command=viewArticleBasic&articleId=9130125&source=NLT_PM

In other words... Mail sent by gmail will be delayed by 5 seconds he you dont want to unsend it.