title: Load magento model that doesn't exist
body: <p>I'm in the process of converting the data from an old website to a new website.  I'm creating and populating customers inside a class that extends <code>Mage_Shell_Abstract</code>.</p>
  
  <p>I want to load a customer if they already exist, or create them if they don't:</p>
  
  <pre><code>$customer = Mage::getModel('customer/customer')-&gt;loadByEmail('none@gmail.com');
  $customer-&gt;setFirstName('John');
  $customer-&gt;setLastName('Smith');
  $customer-&gt;save();
  </code></pre>
  
  <p>Will this code cause any errors if no customer already exists with this email?</p>