In the recent mailbag column http://www.straightdope.com/mailbag/mphasevel.html, Karen made the now-legendary “Speed of Bus” analogy to explain how the phase-velocity could be greater than c while the group (packet) velocity was still c or less. She explained it in terms of passengers on a bus doing “the wave” from back to front.
I learned a different analogy in one of my lower-division college physics classes:
Consider a spinning barber pole. The stripes on the barber pole appear to be moving up the pole or down the pole, depending on which direction the pole is spinning, even though the pole itself is stationary. Now imagine this barber pole hurtling through space lengthwise at the Speed of Barber Pole [TM]. If the pole is spinning in the correct direction, the stripes on the pole will appear to be moving in the same direction as the barber pole is moving, at a speed greater than the Speed of Barber Pole. If the pole is spinning fast enough, these stripes might appear to be moving at several times the Speed of Barber Pole.
But if you’re standing in front of the hurtling barber pole waiting for it to arrive, the stripes aren’t going to hit you before the pole does, will they?