Magento read / write config values from model

You can create Magento config settings using XML files, or… do this directly from model. Here is example:

$value = "My Config Value";
Mage::getConfig()->saveConfig('MyVariableName', $value);
Mage::getConfig()->reinit();
Mage::app()->reinitStores();

Reading this value is much simplier:

$value = Mage::getStoreConfig('MyVariableName');