Netiquette: Undo Send Gives You Five Seconds to Stop a Bum Email:

Wondering what the folks at Google Labs were going to roll out with next? Undo Send lets you do just that within five seconds after pressing send. Did you ever wonder when you were going to be able to do this? Although it is reminiscent of last year's April Fools when they rolled out Google Custom Time for a day, I think it's safe to say that this feature is here to stay. And pretty useful, too, for the times that you regret sending a scathing email just after you pressed send.
What's your favorite Google Labs feature? Alternately, what feature would really save you from awkward situations, like this one promises to? Sound off in the comments.
(Via Lifehacker.)