Here you will be taught how to stretch any image.
1. First Open up the image you want to use. I choose this one.
2. Select the Single Column Marquee Tool.
3. Select the area that you want stretched.
4. Go to Edit > Define Pattern. Call it anything your want.
5. Now used the Rectangualr Marquee Tool select the area to the right or left of the original selection. I selected to the right.
6. Go to Edit > Fill. Select the patter you created in step 4. Its usually the last one. Also make sure the contents box is set to pattern. Press OK and it should look like this.
Extra: Or you can just get rid of the whole picture and use the pixel stretch as the background which sometimes looks better.
More Tutorials: 
