<?php 
 if ($this->helper('customer')->isLoggedIn() ){
  echo '<a href="<?php echo $this->getUrl('customer/account/login/');?>">Login</a>';
 }else {
  echo '<a href="<?php echo $this->getUrl('customer/account/logout/');?>">Logout</a>';
 }
?>

<?php 
 $customer = Mage::getSingleton('customer/session')->getCustomer();
 $email = $customer->getEmail();// for email address
 $firstname = $customer->getFirstname();//  For first name
 $lastnam e= $customer->getLastname();// For last name
?>