Drupal 7 - Print User Picture on page.tpl.php

In your template.php file, add the following..

<?php
function my_theme_preprocess_page (&$variables) {
        if ($variables['logged_in']) {
        $user = user_load($variables['user']->uid);
        if ($user->picture){
        $variables['user_avatar'] = theme_image_style(
                            array(
                                'style_name' => 'thumbnail',
                                'path' =>$user->picture->uri,
                                'attributes' => array(
                                'class' => 'avatar'
                                    ),
                                'width' => NULL,
                                'height' => NULL,            
                                )
                            );
        }
        else{
            $variables['user_avatar'] =  '<a title="Profile" href=/user><img src="/sites/all/themes/my_theme/images/default.png" /></a>';
                }
        }
        else {
            $variables['user_avatar'] = '<img src="/sites/all/themes/my_theme/images/default.png" />';
                    }
}

Then go to your page.tpl.php and add the following to the section where you want the picture to appear:

<a title='Profile' href=/user><?php print $user_avatar; ?></a>