Views Menu Tabs and Ajax?
If you want to user tabs and have blocks inside them coming from then, then one very beautiful module which you can use is Drupal Quick tabs: http://drupal.org/project/quicktabs

This module works amazingly. It also takes arguments and allow you to do a lot of advanced modifications like Ajax call to the tabs or directly load them etc. You can check the Techtree website for an example of quick tabs that we have used in the side bar.