To make a similar border:
Open a new image in Photoshop.
Create a black layer over a white layer (You could do white on black, but it's easier for me to see what I'm doing this way, I'll invert it later to make the border white)
Create a layer mask on the black layer (Image 1)
With the layer mask selected, use a rectangular marquee over the center of the image and fill it with black (to mask it out) (Image 2)
Use a jagged edged brush and paint on the layer mask (with black) over the hard edges left from the rectangle (Image 3)
Touch up the edges as you see fit
Select the black layer (not the mask) and invert it to make the border white; also invert the white layer to make it black so you can see the border (image 4)
Insert your background image under the border layer (image 5)
Alternately: It looks like the border you have is kind of scratched paper... If you want that exact effect, you can create it by taking a lead pencil and scribbling the shape of the border on a piece of paper. What you do with the pencil should be the white area of the border. Then you can scan your drawing as black and white, bring up the contrast to tweak the edges as needed, then create an alpha channel from the black part of the drawing. Obviously this is more time consuming than the method above, and would only be used if you need that exact effect.
