I'm told that the instant a photon leaves, say, a flashlight, that it is instantaneously traveling at the speed of light, without accelerating from 'rest' to reach that speed. In consideration of Quantum Mechanics, the Heisenberg Uncertainty Principle, Planck's Constant, String Theory, and whatever else, is this a correct statement?

I believe it is instantaneous. What I am curious about is, is this the real physical shape of light. I saw this on several pages of a "diagram" of how light works but is this how light appears in real third dimentional space? Here's one of the pages that shows this diagram: http://micro.magnet.fsu.edu/primer/java/scienceopticsu/electromagnetic/index.html