This is a nice little roundup of some great little jQuery tools for navigation. From widgets to full blown site nav. Great little article, Web Design Ledger guys.
15 Excellent jQuery Navigation Techniques and Solutions | Web Design Ledger:
"Along with content, most would agree that navigation is one of the most important aspects of any website. That’s why it’s crucial to make site navigation intuitive and engaging. jQuery is an excellent choice for achieving this. There are many things you can do with jQuery to spice up menus, but here are 15 of the best techniques and solutions for enhancing website navigation."