Yahoo has announced it will give away the browser-based authentication used in its email service, considered to be the company's 'crown jewels.' Yahoo made the announcement ahead of a 24-hour 'Yahoo Hack Day,' where it had invited more than 500 mostly youthful outside programmers to build new applications using Yahoo services. Considering the different needs of its huge user base (257 million people use Yahoo Mail), Yahoo has decided it can't build or buy enough innovation, so they are enlisting the worldwide developer community.