Create 2500 dummy configurable products in a Magento installation for testing purposes.

Create_Configurable_Products.php

<?php
/**
 * Error reporting
 */
error_reporting(E_ALL | E_STRICT);

/**
 * Compilation includes configuration file
 */
define('MAGENTO_ROOT', getcwd());
$mageFilename = MAGENTO_ROOT . '/app/Mage.php';
require_once $mageFilename;
if (isset($_SERVER['MAGE_IS_DEVELOPER_MODE'])) {
    Mage::setIsDeveloperMode(true);
}
umask(0);
/* Store or website code */
$mageRunCode = isset($_SERVER['MAGE_RUN_CODE']) ? $_SERVER['MAGE_RUN_CODE'] : '';

/* Run store or run website */
$mageRunType = isset($_SERVER['MAGE_RUN_TYPE']) ? $_SERVER['MAGE_RUN_TYPE'] : 'store';
Mage::app();



/* Create attribute */
/** @var $installer Mage_Catalog_Model_Resource_Setup */
$installer = new Mage_Catalog_Model_Resource_Setup('catalog_setup');
/** @var $attribute Mage_Catalog_Model_Resource_Eav_Attribute */
$attribute = Mage::getResourceModel('catalog/eav_attribute');
$attribute->load('test_configurable', 'attribute_code');
if ($attribute->getId() == null) {
    $attribute->setData(
        array(
            'attribute_code'    => 'test_configurable',
            'entity_type_id'    => $installer->getEntityTypeId('catalog_product'),
            'is_global'         => 1,
            'is_user_defined'   => 1,
            'frontend_input'    => 'select',
            'is_unique'         => 0,
            'is_required'       => 1,
            'is_configurable'   => 1,
            'is_searchable'     => 0,
            'is_visible_in_advanced_search' => 0,
            'is_comparable'     => 0,
            'is_filterable'     => 0,
            'is_filterable_in_search'   => 0,
            'is_used_for_promo_rules'   => 0,
            'is_html_allowed_on_front'  => 1,
            'is_visible_on_front'       => 0,
            'used_in_product_listing'   => 0,
            'used_for_sort_by'          => 0,
            'frontend_label' => array(
                0   => 'Test Configurable'
            ),
            'option' => array(
                'value' => array(
                    'option_0'  => array(0 => 'Option 1'),
                    'option_1'  => array(0 => 'Option 2'),
                ),
                'order' => array(
                    'option_0' => 1,
                    'option_1' => 2,
                )
            ),
            'backend_type' => 'int',
        )
    );
    $attribute->save();

    /* Assign attribute to attribute set */
    $installer->addAttributeToGroup('catalog_product', 'Default', 'General', $attribute->getId());
}

/* Create simple products per each option */
/** @var $options Mage_Eav_Model_Resource_Entity_Attribute_Option_Collection */
$options = Mage::getResourceModel('eav/entity_attribute_option_collection');
$options->setAttributeFilter($attribute->getId());

for ($i = 1; $i <= 2500; $i++) {
    $attributeValues = array();
    $productsData = array();
    foreach ($options as $option) {
        /** @var $product Mage_Catalog_Model_Product */
        $product = Mage::getModel('catalog/product');
        $product->setTypeId(Mage_Catalog_Model_Product_Type::TYPE_SIMPLE)
            ->setId($i * 10000 + $option->getId() * 10)
            ->setAttributeSetId($installer->getAttributeSetId('catalog_product', 'Default'))
            ->setWebsiteIds(array(1))
            ->setName('Configurable Option' . $option->getId() . '-' .  $i)
            ->setSku('simple_'.$option->getId() . '_' . $i)
            ->setPrice(10)
            ->setTestConfigurable($option->getId())
            ->setVisibility(Mage_Catalog_Model_Product_Visibility::VISIBILITY_NOT_VISIBLE)
            ->setStatus(Mage_Catalog_Model_Product_Status::STATUS_ENABLED)
            ->setStockData(
            array(
                'use_config_manage_stock'   => 1,
                'qty'                       => 100,
                'is_qty_decimal'            => 0,
                'is_in_stock'               => 1,
            )
        )
            ->save();

        $dataOption = array(
            'label'         => 'test',
            'attribute_id'  => $attribute->getId(),
            'value_index'   => $option->getId(),
            'is_percent'    => false,
            'pricing_value' => 5,
        );
        $productsData[$product->getId()] = array($dataOption);
        $attributeValues[] = $dataOption;
    }

    /** @var $product Mage_Catalog_Model_Product */
    $product = Mage::getModel('catalog/product');
    $product->setTypeId(Mage_Catalog_Model_Product_Type::TYPE_CONFIGURABLE)
        ->setId($i)
        ->setAttributeSetId($installer->getAttributeSetId('catalog_product', 'Default'))
        ->setWebsiteIds(array(1))
        ->setName('Configurable Product')
        ->setSku('configurable_' . $i)
        ->setPrice(100)
        ->setVisibility(Mage_Catalog_Model_Product_Visibility::VISIBILITY_BOTH)
        ->setStatus(Mage_Catalog_Model_Product_Status::STATUS_ENABLED)
        ->setStockData(
        array(
            'use_config_manage_stock'   => 1,
            'is_in_stock'               => 1,
        )
    )
        ->setConfigurableProductsData($productsData)
        ->setConfigurableAttributesData(
        array(
            array(
                'attribute_id'  => $attribute->getId(),
                'attribute_code'=> $attribute->getAttributeCode(),
                'frontend_label'=> 'test',
                'values' => $attributeValues,
            )
        )
    )
        ->save();

    echo '.';
    if ($i % 100 == 0) {
        echo "\n$i\n";
    }
}