This is a pretty funny feature Google Labs decided to release. This is for GMail only, however. It's called Mail Goggles. It's to prevent those who get a little tipsy at night and accidently send off that late night email about a crush, or some "important" company documents that were accidently sent out "drunkenly". Well this is to stop it, by what means?
Math.
By default, Mail Goggles is only enabled on late night Fridays and Weekends, the times you really only need it (hopefully). You can also change the settings so you can prevent it for all nights of the week (love drinking?).
Now, the only thing Google needs to do is to implement this feature on their next Android platform phone too for text messaging.
