mau gnsjtagmailcom know right cant get information users email address based authsub fine im sure many users would like know well answer one point security issue hard give us user hash md5 maybe using username data appid salt better still cant reveng data internal google user_id app_id salt md5 understand doesnt take storage large memory cycles return us dont even store way could track returning users internet users google hotmail yahoo aim hold keys ridding internet register step websites yahoo aim already taken initiative allow users login authorized websites live working passport provide us ways tie user back accounts look yahoo httpdeveloperyahoocomauthuserhtml send_userhash optional parameter equals 1 yahoo login server includes unique identifier particular user endpoint url userhash identify returning user even build application requires sign without build authentication part identifier bound specific appid look aol httpdevaolcomopenauth_api get_info validates authentication token issued returns users loginid displayname along last authentication time stamp getinfo method invoked browser either redirect json jsonp call browser mean right asking received message subscribed google groups codesitediscuss group post group send email piletdshipxesgggooglegroupscom unsubscribe group send email bfjlklzasawamprsbfjlklzasagooglegroupscom options visit group httpgroupsgooglecomgroupcodesitediscuss wed 06 aug 2008 020003 0000 auth sub get email ever changing session token