There’s a new GMail Labs app: Mail Goggles, by GMail engineer Jon Perlow:
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? … Hopefully Mail Goggles will prevent many of you out there from sending messages you wish you hadn’t. Like that late night memo — I mean mission statement — to the entire firm.