Automatically select shipping method in magento

Have you ever stuck with automatically select shipping method in magento ?
For example in this tutorial, we assumed that we had only one shipping method : free-shipping. So, we need to set it as default shipping method and ignore shipping step.
We can make it done with these simple steps:

1/Create app/etc/modules/Inbusiness_Checkout.xml

<?xml version="1.0"?>
<config>
<modules>
<Inbusiness_Checkout>
<active>true</active>
<codePool>local</codePool>
</Inbusiness_Checkout>
</modules>
</config>

2/Create app/code/local/Inbusiness/Checkout/etc/config.xml

<?xml version="1.0"?>
<config>
<modules>
<Inbusiness_Checkout>
<version>1.1.1</version>
</Inbusiness_Checkout>
</modules>
<frontend>
<routers>
<checkout>
<use>standard</use>
<args>
<modules>
<Inbusiness_Checkout before="Mage_Checkout">Inbusiness_Checkout</Inbusiness_Checkout>
</modules>
</args>
</checkout>
</routers>

</frontend>
</config>

3/ Create app/code/local/Inbusiness/Checkout/controllers/OnepageController.php

<?php
require_once 'Mage/Checkout/controllers/OnepageController.php';

class Inbusiness_Checkout_OnepageController extends Mage_Checkout_OnepageController
{

public function saveBillingAction()
{
if ($this->_expireAjax()) {
return;
}
if ($this->getRequest()->isPost()) {
//            $postData = $this->getRequest()->getPost('billing', array());
//            $data = $this->_filterPostData($postData);
$data = $this->getRequest()->getPost('billing', array());
$customerAddressId = $this->getRequest()->getPost('billing_address_id', false);

if (isset($data['email'])) {
$data['email'] = trim($data['email']);
}
$result = $this->getOnepage()->saveBilling($data, $customerAddressId);

if (!isset($result['error'])) {
/* check quote for virtual */
if ($this->getOnepage()->getQuote()->isVirtual()) {
$result['goto_section'] = 'payment';
$result['update_section'] = array(
'name' => 'payment-method',
'html' => $this->_getPaymentMethodsHtml()
);
} elseif (isset($data['use_for_shipping']) && $data['use_for_shipping'] == 1) {
$result['goto_section'] = 'shipping_method';
$result['update_section'] = array(
'name' => 'shipping-method',
'html' => $this->_getShippingMethodsHtml()
);

$result['allow_sections'] = array('shipping');
$result['duplicateBillingInfo'] = 'true';

$method = 'freeshipping_freeshipping';
$result = $this->getOnepage()->saveShippingMethod($method);

if(!$result) {
Mage::dispatchEvent('checkout_controller_onepage_save_shipping_method',
array('request'=>$this->getRequest(),
'quote'=>$this->getOnepage()->getQuote()));
$this->getOnepage()->getQuote()->collectTotals();
$this->getResponse()->setBody(Mage::helper('core')->jsonEncode($result));

$result['goto_section'] = 'payment';
$result['update_section'] = array(
'name' => 'payment-method',
'html' => $this->_getPaymentMethodsHtml()
);
}
$this->getOnepage()->getQuote()->collectTotals()->save();
} else {
$result['goto_section'] = 'shipping';
}
}

$this->getResponse()->setBody(Mage::helper('core')->jsonEncode($result));
}
}

/**
* Override Shipping address save action
*/

public function saveShippingAction()
{
if ($this->_expireAjax()) {
return;
}
if ($this->getRequest()->isPost()) {
$data = $this->getRequest()->getPost('shipping', array());
$customerAddressId = $this->getRequest()->getPost('shipping_address_id', false);
$result = $this->getOnepage()->saveShipping($data, $customerAddressId);

if (!isset($result['error'])) {

$method = 'freeshipping_freeshipping';
$result = $this->getOnepage()->saveShippingMethod($method);

if(!$result) {
Mage::dispatchEvent('checkout_controller_onepage_save_shipping_method',
array('request'=>$this->getRequest(),
'quote'=>$this->getOnepage()->getQuote()));
$this->getOnepage()->getQuote()->collectTotals();
$this->getResponse()->setBody(Mage::helper('core')->jsonEncode($result));

$result['goto_section'] = 'payment';
$result['update_section'] = array(
'name' => 'payment-method',
'html' => $this->_getPaymentMethodsHtml()
);
}
$this->getOnepage()->getQuote()->collectTotals()->save();

}
$this->getResponse()->setBody(Mage::helper('core')->jsonEncode($result));
}
}

}

Happy coding !