<p>As of now, this is not possible.  Please see <a href="http://meta.stackexchange.com/questions/73792/how-do-i-add-stack-exchange-2-0-sites-to-my-cv-on-careers-stackoverflow-com">this post on Meta.SO</a> for more information.</p>

<p>As Korneel mentions, for a workaround, you can add your <a href="http://askubuntu.com/users/flair">flair</a> to one of the text fields that support markdown (though it isn't identical to the options for the Trilogy sites).</p>