MAGICAL BLURRING TECHNIQUE

1. Duplicate the Background layer. Do this by first selecting the layer in the layers palette, then choosing Layer -> Duplicate layer.

2. Select the duplicate layer and choose Filter -> Blur -> Lens Blur. Choose the desired blurring radius and click OK.

3. Make sure the blurred duplicate layer is on top of the non-blurred layer.

4. Attach a layer mask to the blurred layer by choosing Layer -> Layer Mask -> Reveal All.

5. You can now reveal and hide the blurry layer just as you would on an adjustment layer mask.

6. Presto. See below for a before and after example.