Street view provides real world images of many major towns & cities but navigating these images in Google Maps was only possible by clicking on forward and back arrows to move through space. Now, (as you can see in the quick demo video below) smart navigation allows you to use these real-world images themselves to navigate around. Just place a cursor on the actual building or point on the map that you want to view and double-click.
Smart Navigation for Street View UI
by Luke Wroblewski June 5, 2009