Is is possible to add additional navigation menu items to the page menu bar? I want to add two links to off-site URLs to the page menu bar and I want these two links to look just like the existing page menu links. The Techozoic-fluid allows this, and I was wonder if it was possible with Atahualpa or not.

yes it is, search the form the question has been answered before and if you use the new wp 3+ menu, you can add it with ease