A problem commonly encountered during layout of a 2D film is that of getting nice and smooth camera movements when your camera is zooming and panning at the same time, that is, rotating about its center. This article demonstrates a camera setup we created to solve this problem, available as an addon.
On the top view it's a usual 3D camera, with start/end position/rotation/lens keyframes. Look at the bottom-left corner wiggling around. On the bottom view however, that corners stays put.