Stop sending mail you later regret: This has got to be a joke. I can’t find it in my Gmail this morning, at any rate.
When you enable Mail Goggles, it will check that you’re really sure you want to send that late night Friday email. And what better way to check than by making you solve a few simple math problems after you click send to verify you’re in the right state of mind?
Nope. It's really there. But you have to enable the Gmail labs for your account. It's one of the lab items.