How do you allow users to create own menus?
Menu Admin Per Menu Module comes to solve this purpose!!


  The Drupal 7 Menu Admin Per Menu module is a simple module that allows
  you to grant permissions for users to administer specific Drupal menus
  based on their role. 
  
  This module for instance would allow you to allow one role to modify
  the Main menu, while not allowing the role to modify a separate menu
  on your Drupal 7 website.


Watch this Screencast to learn about it : How to allow a specific role to administer the user menu on a Drupal site without giving them access to modify the Main menu