Description:
------------
<?php
  session_start();
  if (!isset($_SESSION['name'])){
    $_SESSION['name'] = 'Richard Lynch';
  }
  else{
    $name = $_SESSION['name'];
  }
  /* Assume a ton of code goes here */
  $name = 'Fooey';
  echo "Session name is: ", $_SESSION['name'], "<br />\n";
?>

Now, hit this page, re-load it, and what do *YOU* expect $_SESSION['name'] to output?

A) 'Richard Lynch', because you never re-assigned $_SESSION['name']
B) 'Fooey' because $name is a reference, and you changed it, so that changed your session data.

*I* expected A)
Alas, the reality is B)