Gimp Tutorial :: Rounded Borders - Indestructable Box

1) new image, with transparent background
2) select all
3) stroke with 1px (no aliasing) color of border
4) select top 10% of image
    a) copy and paste into new transparent layer
    b) anchor layer
    c) in layers dialog, go back to original layer with entire border
5) select inverse (remainging 90% of image)
    a) copy and paste into new transparent layer
    b) anchor layer
    c) in layers dialog, go back to original layer with entire border
6) select left 10% of image
    a) copy and paste into new transparent layer
    b) anchor layer
    c) in layers dialog, go back to original layer with entire border
7) select inverse (remaining 90% of image)
    a) copy and paste into new transparent layer
    b) anchor layer
    c) in layers dialog, go back to original layer with entire border
8) Go to each corner, and perform the "Mountain Steps" as described by Dan Cederholm on alistapart.com
    a) set pencil tool at 1px
    b) 4 white squares in corner + 2 more going in each direction.
    c) remaining squares should be border color with "m" shape

http://www.alistapart.com/articles/mountaintop/