Ok, here is what i did.
pretending i started with the image full frame (ie, no white border)....I copied the image to a new canvas with a transparent background.
1: I used the select tool to create a corner...one vertical, hold shift, one horizontal...which gave me an upside down L
2: Create new layer, fill selection with white
3: Line up "L" with corner
4: Create another new layer
5: with the polygonal lasso, I started my selection at the top of the corner, worked my way down the side, gradualy moving closer to the border
6: click, diagonal line up the right....resume selection at right part of top "L"
7: gradually increase height to meet the top left corner
8: Fill selection with greyish color
9: adjust opacity of layer to thin it out
10: apply slight gaussian blur to layer to simulate drop shadow effect
11: smooth out edges if needed with eraser.
12: Enjoy :-)
EDIT: ok, file upload doesnt want to work for me....so here
http://aycu01.webshots.com/image/145...3372249_rs.jpg