The Zoom Effect

I recently noticed that some photographers utilize what is commonly called the "zoom effect" to give a sense of motion to their photos, leaving the subject centered and in-focus while everything else is blurred. People can get this effect through post-processing work or alternately by moving the camera close to the subject or using a telephoto lens and smoothly zooming in on the subject during a longer exposure.

Examples and tutorials below!


http://www.flickr.com/photos/casch/258138934/

Tutorials:

http://www.behance.net/gallery/Urban-Zoom/333146
http://dptnt.com/2007/10/the-zoom-effect/
http://www.digital-photography-school.com/using-the-zoom-effect