I’ve been experimenting with modifying a copy of the Joomla “profile” plugin (/plugins/users/profile) and adding custom profile fields to use in other Components. Retrieving those stored profile values required some research, but it turns out it’s pretty straight-forward:

$User = JFactory::getUser();
$Profile = JUserHelper::getProfile(User->id);

From there, it may be easiest to just use the print_r() function to see what properties are available. In my case, they were in the “profile” property of the $Profile object, which was an array. So:

$favorite_goat = $Profile->profile['favorite_goat'];