Scaling the distance between objects [duplicate]

I've got a camera tracked to an empty, and I'd like to add keyframes with constant interpolate to have the camera "click" forward.

How can I scale the distance between objects, without affecting their size? Even better would be setting an absolute value of the distance between the objects.

• Thanks. It turned out that I could accomplish what I was looking for by extruding faces along their normals (ezz) – ajwood Jan 22 '14 at 20:45