Google Mail Goggles is a new feature available through Gmail to help prevent those late night drunken emails to exes, co-workers, evil park keepers etc.
You can set it to be active at the times you’re most likely to be drunk in charge of a PC, and it will give you a few simple maths questions just to make sure you’re coherent and in charge of your faculties.
I don’t think I’ve ever sent a regrettable email due to drinking, but I don’t think this would stop me really as the questions are very easy!
Examples include:
69-38
11 x 2
2 x 5
and so on..I’m pretty sure even if I was so wasted I thought it would be a good idea to email all of America and say that Tina Fey sucked, I could still answer those problems correctly!
At least they tried right?!
Cloudy with a chance of Licensing 
I think its great as it shows Google has a sense of humour, plus it is actually quite useful. I’ve often sent things in a rush, re-read my sent version and cringe!