If you, like me, like to have a Login tab in K2 here’s how to do it:

  1. Open wp-content/themes/k2/header.php
  2. Find the line:
    <?php wp_register('<li class="admintab">','<li>'); ?>
  3. Replace it with:
    <?php wp_register('<li class="admintab">',''); ?>
    <?php wp_loginout(); ?></li>
  4. Save it.