One of the best radial blur effects I have seen. Most never seem to quite pull it off. But I reckon you have really nailed it.
old ucci
Thank you, Ken. The trick is to first make a duplicate layer of the shot. Then draw a circle (or other shape if it suits the shot) using the marquee tool around the area that you do NOT want blurred on the layer copy. You then feather that selection (the amount depends on the shot), and then invert the selection so the area outside the circle is selected and feathered. Then you apply the radial blur using the 'zoom' option and the outer area becomes zoomed. As well as being able to adjust the zoom level in the blur dialogue box, you can also reduce the effect by reducing the opacity of the layer from 100%. Here's another one, where I have reduced the effect by reducing the opacity. It's Snowdon. This effect works best on a subject that sits in the centre of the shot, and has it's own radial structure to start with - such as a flower. As well as reducing the layer opacity, you can also change the blend mode.
Great shot and explanation of the technique.