LiveUser - meta information for users

Hello, I am using LiveUser with XML_Simple containers like in example 2. I woulde like to display some meta information about the logged in user like the full name or the email-address. My first try to add them to the Auth_XML.xml like <user>

    <userId>c4ca4238a0b923820dcc509a6f75849b</userId>
    <handle>Charlotte</handle>
    <fullname>Charlotte Clip</fullname>
    <email>test@server.com</email>
    <password>098f6bcd4621d373cade4e832627b4f6</password>
    <currentLogin>1047564897</currentLogin>
    <lastLogin>1105695478</lastLogin>
    <isActive>Y</isActive>

</user> and fetch the information with $LU->getProperty('email') obviously was too naive. How would it be possible to handle additional user information with LiveUser and XML_Simple containers? Kind regards, Joerg Bruckmann