Easiest way to create a continuous shot effect using multiple cameras?
CG is probably the best bet.  Motion controlled cameras would be the second best bet, but it would still be pretty tricky as the real world has a remarkable ability to change subtly, but substantially enough to result in a jump cut pretty quickly.  Even if you could manage to stop the camera on something that is static, resuming the movement at the same speed would be difficult at best without a computer controlled camera.  

If you are able to have the camera stop movement on scenery in between, that might make a possible stop point, but it would still have to be done pretty quickly to avoid changes in lighting conditions that would be noticeable in the final shot.