Yahoo! 360 Beta is finally online and Yahoo! Says ;
Yahoo! 360 is now an invitation-only beta service, which means you must receive an invitation from Yahoo! or a friend to sign up for the service. However, we plan to open up the beta to more people in the coming weeks. We’d like to invite you to join us at that time.
More information can found about Yahoo! 360 and here Yahoo! 360 beta list