Well, that is pretty simple but in case someone will need this, just:

$product = Mage::getModel('catalog/product')->load(123);
$inStock = Mage::getModel('cataloginventory/stock_item')->loadByProduct($product)->getIsInStock();

In case someone will need this, it’s quite simple:

$order = Mage::getModel('sales/order')->load( 1234 );
$shipment = Mage::getModel('sales/service_order', $order)->prepareShipment(array());
$shipment->register();
$shipment->getOrder()->setCustomerNoteNotify(false);
$shipment->getOrder()->setIsInProcess(true);
$transactionSave = Mage::getModel('core/resource_transaction')->addObject($shipment)->addObject($shipment->getOrder())->save();

Preparing such export is quite easy, so let’s begin with adding new button in products listing:

in app/code/core/Mage/Adminhtml/Block/Catalog/Product.php in _prepareLayout() function add such code:

$this->_addButton('export_fact', array(
    'label'   => Mage::helper('catalog')->__('FACT-Finder'),
    'onclick' => "setLocation('{$this->getUrl('*/*/exportfact')}')",
    'class'   => 'add'
));

then in app/code/core/Mage/Adminhtml/controllers/Catalog/ProductController.php add new function:

public function exportfactAction()
{
    $productCollection = Mage::getModel('catalog/product')->getCollection();

    $csv = '"ProductID";"ProductName";"Description";"Price"'."\n";

    foreach ($productCollection as $item)
    {
        $data = $item->getData();

        $product = Mage::getModel('catalog/product')->load($data['entity_id']);

        $csv.= '"'.sprintf("%09d", $product->getId()).'";"'.$product->getName().'";"'. strip_tags($product->getShortDescription() ).'";"'.sprintf("%.2f", $product->getPrice()).'"'."\n";
    }
    $this->_prepareDownloadResponse('fact.csv', $csv);
}

and thats all. You will get new button with export ability.

Today I had to change Magento default products list sorting to sort by product’s date. In fact we don’t need to sort by date, just by entity_id which is product ID in Magento world. To accomplish this, we need to edit /app/code/core/Mage/Catalog/Block/Product/List.php

You have to find _beforeToHtml() function and change some things inside. First we need to define all available sorting options:

$orders = array('entity_id' => $this->__('Newest'), 'name' => $this->__('Name'), 'price' => $this->__('Price') );

then remove all getters of default sorting and order, and put those:

$toolbar->setAvailableOrders($orders);
$toolbar->setDefaultOrder('entity_id');
$toolbar->setDefaultDirection('desc');

so finally your _beforeToHtml() should looks like this one:

protected function _beforeToHtml()
{

    $toolbar = $this->getToolbarBlock();

    // called prepare sortable parameters
    $collection = $this->_getProductCollection();

    // use sortable parameters
    $orders = array('entity_id' => $this->__('Newest'), 'name' => $this->__('Name'), 'price' => $this->__('Price') );
    $toolbar->setAvailableOrders($orders);

    $toolbar->setDefaultOrder('entity_id');

    $toolbar->setDefaultDirection('desc');

    if ($modes = $this->getModes()) {
        $toolbar->setModes($modes);
    }

    // set collection to tollbar and apply sort
    $toolbar->setCollection($collection);

    $this->setChild('toolbar', $toolbar);
    Mage::dispatchEvent('catalog_block_product_list_collection', array(
        'collection'=>$this->_getProductCollection(),
    ));

    $this->_getProductCollection()->load();
    Mage::getModel('review/review')->appendSummary($this->_getProductCollection());
    return parent::_beforeToHtml();
}

Maybe someone will need it, so here we go with code:

echo "<pre>";
$category = Mage::getModel('catalog/category');
$tree = $category->getTreeModel();
$tree->load();

$ids = $tree->getCollection()->getAllIds();
$categories = array();
if ($ids)
{
    foreach ($ids as $id)
    {
        $category->load($id);
        $categories[$id]['name'] = $category->getName();
        $categories[$id]['path'] = $category->getPath();
    }
    foreach ($ids as $id)
    {
        $path = explode('/', $categories[$id]['path']);
        $string = '';
        foreach ($path as $pathId)
        {
            $string.= $categories[$pathId]['name'] . ' > ';
            $cnt++;
        }
        $string.= ';' . $id . "\n";

        echo $string;
    }
}

the snippet above will give you such output:

root category 1 ; 1
root category 1 > subcategory 1 ; 2
root category 1 > subcategory 1 > subsubcategory 1 ; 3
root category 1 > subcategory 1 > subsubcategory 2 ; 4
root category 1 > subcategory 2 ; 5
root category 1 > subcategory 2 > subsubcategory 1 ; 6