Used it here a lot...
took the single pixel marquee, copied then pasted on a new layer.
Then nudged then pasted. I think someone settled it earlier.
actually took that single line marquee, copied part of the image, then using transform, Stretched it.
Since no one covered this yet, I would select an area that's one pixel deep and stretch it using the transform tool.
psst.. look above haha.
ps>3d