The thing is, in order for their to be a blur, something has to move in the shot. Either a person or the background, and you have to use strobe to make something crisp and standout against the blur. I did something like this once when I was hired to shoot a produce warehouse (don't ask - it was a long time ago). I did one shot on a loading dock with a slow shutter (probably about 1/4 or 1/2 second) with the f-stop adjusted for the speed. Then I had a worker with a hand-truck full of boxes move through the shot, and lit him with a stobe balanced for that same f-stop. So...... he blurred (motion) in the shot to the point where the strobe was fired, as which point he became sharp, while the backgound stayed sharp. (Wish I could find the film to show you, it looked great). If you wanted to do it in reverse, you would probably have to do it all with ambient light, and you'd have to pan the camera with the worker, so the worker stayed sharp while the background blurred. You could also strobe him, but you'd still have to pan to blur the background. It will take a few exposures to get it right, but if you're not doing it on digital, I'd take a few Polaroids first.
Andy Pearlman Studio