A crazy password-less login system

For what it's worth, it's not new. My latest project, Fork the Cookbook (<a href="http://forkthecookbook.com" rel="nofollow">http://forkthecookbook.com</a>) uses a similar system

<a href="http://www.marco.org/2013/02/24/the-magazine-sharing" rel="nofollow">http://www.marco.org/2013/02/24/the-magazine-sharing</a>