High speed barrel

Originally taken for the digital camera marathon in Bordeaux this week end, i wanted to make some adjustments... i quite like the effect i got.
to achieve this, just set the camera on speed priority, set 1/4s approx (you need to adjust with the ambient light) and prepare to zoom in and/or rotate the camera during the time between the open clik, and the close clic... dont know if i'm clear it only works with manual zoom lenses...