The Sunnyvale-based company plans to integrate the Facebook Connect service with Yahoo's email, news and photo services, allowing you to quickly update your Facebook status, for instance, and share content on Yahoo sites.
Yahoo, once the mightiest Web company around, has been struggling to compete with upstarts like Google, which devoured its search business, and Facebook, which offered the social networking services that would have been a natural fit with Yahoo.
In the case of Search, Yahoo essentially outsourced that business to Microsoft in a deal to send users to and sell ads on Bing.
In this case, Yahoo is presumably hoping that being able to click to share a photo on Facebook will keep a user hanging out at Flickr instead of clicking over to Facebook or ditching the service entirely.
But the big winner may be Facebook, which will get that much information about their users to track for advertisers even while those users are hanging out on Yahoo.
Jackson West used to love Yahoo, but now rarely hangs out with her.