gistfile1.php

<?php
class SomeModel extends Model {
function doSomething ($foo) {
    // need to work with another model...
    $CI =& get_instance();
    $CI->load->model('SomeOtherModel','NiceName',true);
    // use $CI instead of $this to query the other models. Shorter anyway ;-)
    $CI->NiceName->doSomethingElse();
}
?>