title: PHP str_replace to replace numbers with words
body: <p>I have a website that needs to display phone numbers to users, but rather than display the actual number for someone to harvest from the source code, I'd like to replace each digit of the phone number with the corresponding word.  For instance...</p>
  
  <pre><code>355-758-0384
  
  Would become
  
  three five five - seven five eight - zero three eight four
  </code></pre>
  
  <p>Can this be done?  Sorry, I don't have any code to display because I don't even know where to start with this.</p>