I shall not re-invent the wheel and talk in details. Check out the following links. Essentially this method is about taking many pictures (like what you do for a panaroma stiched shots) with a medium telephoto lens (or longer) @ wide open aperture. These pictures are then stiched together using stiching application (application must support 2D stiching which is vertical and horizontal). The bokeh and perspective effect is like having a wide angle lens @ F1.0 or less!
http://blog.buiphotos.com/2009/07/the-brenizer-method-explained-with-directions/
