From http://stackoverflow.com/questions/8124089/get-value-of-custom-user-field-in-drupal-7-template

get_user_profile_field_with_entity_wrapper.php

<?php
function THEME_preprocess_page() {
  global $user;
  $user = user_load($user->uid); // Make sure the user object is fully loaded
  $wrapper = entity_metadata_wrapper('user', $user);
  $vars['full_name'] = $wrapper->field_full_name->value(array('sanitize' => TRUE));
}