Auto-create navigation link to a node
To achieve this I wrote a module, which creates a node on user create. The node has an alias, which is the username. Code below: 

function mymodule_user_insert(&amp;$edit, $account, $category) {
    $node = new stdClass();
    $node-&gt;type = 'article';
    node_object_prepare($node);

    $node-&gt;title = $edit['name'];
    $node-&gt;path = array(
        'alias' =&gt; $edit['name'],
    );
    $node-&gt;uid = $account-&gt;uid;
    $node-&gt;language = LANGUAGE_NONE;
    node_save($node);
}


Additionally I used MENU_TOKEN module, which allows to input tokens into title and path of menu links. So my new navigation link path is [current-user:name], which links user's article to his profile. 

EDIT: Of course in the example I used 'article' as content type, but in practice I use a custom content type. So if you want to use this code, make sure this line: 

$node-&gt;type = 'article';


is adjusted as per requirements.