title: When to call a "require" in Rails?
body: <p>I have a more conceptual question in Rails... or Ruby for that matter:</p>
  
  <p>Is it best to call a require right before the method that needs it, group my requires at the beginning of the class or somewhere in an initializer when Rails boots?</p>
  
  <p>Does it matter from a performance point of view? From a readability point of view? Does it make a difference if I'm using Rails 3?</p>
  
  <p>Thanks!</p>