• Log into flickr with your Yahoo! ID
  As of now, anyone can log in to Flickr using their Yahoo! ID. New users will have to use their Yahoo! ID (or create a new one if they don't have one); older users can continue to use their existing Flickr.com account details to log in, or choose to merge their Flickr.com accounts and Yahoo! IDs together*. One note: Existing users will be able to keep their existing screen names on Flickr whether they choose to merge accounts now or not - you don't have to change your name.
  in Public bookmarks with flickr identity password yahoo

identity from all users