Stretching Background

[seattlegrace]

I used to know how to do this, and I've lost it.
image example:

http://bewareofninja.com/demo/skins/safari/images/top_image.png

See how the background is, essentially, "stretched".
I can't remember how I did it once and I'd like to use it again.

Help?

 

[jconingham]

Select the area that you want to "stretch" and aply a gaussian or motion blur.