My buddy and design counterpart at work whipped up a tab navigation for a SharePoint client who needed navigation between web part pages. You can put this code into a content editor web part and have insta-nav on your web part pages. Here is a preview:
The ZIP file contains the HTML code with CSS and the images to create the tabs. You can of course tweak to your liking for your own design. And this isn't just for SharePoint, you can use it for any web site.
» Download the ZIP file for tab nav
Chris, who wrote this code, likes to blog about fish and stars and other stuff that shows he has a life. So he generously offered that I could post his tab nav on my site. If you have any questions though, bug me via post comments or my contact form. Leave Chris please to play with his family and fish. :-)