James wrote about the new NASA Photosynth collections a couple of days ago. I really like the way the descriptive text includes links to areas of the Photosynth image.
Here's a case in point - click on the "struts" link whilst viewing the collection navigates you to the appropriate area of the composite image:
"The planes themselves differ in several ways from traditional 747s. The most visible are the three struts protruding from the top..."