Dark Edges or Vignettes are often used to direct the focus to the centre of the photo and away from the clutter of the background. It’s good for portraits where the character is in the centre.
First off, you need to have Adobe Photoshop. I am using Adobe Photoshop CS2.
1) First open up your photo in Adobe photoshop. Go to Create New Layer. Shift+Ctrl+N in windows.
2) Use the Paint Bucket tool to Paint the layer White.
3) Open up Layer Style by double clicking the white layer in the layer window at the right corner.
4) This brings up the Layer Style window. Tick Inner Shadow and Set it according to this pic. Distance and Choke at 0% and 0px, size at 250px, Opacity at 100%.
5) Still in the Layer Style window, go to Blending Options: Default. Under Advanced Bleeding, Drag the Fill Opacity to 0%. You’re done! I just did Auto Contrast and Auto Levels to make the colour look nice a bit.