A very good friend of mine showed me a trick the other day and I thought I should share. Using a colored photo of your choice, duplicate the photo layer and move on to step two.
Now go to the main menu and select "Image" then "Adjustments", and lastly "Desaturate."
Now go back to your colored layer, drag it to the top of the layer pallet and using the "Eliptical Marquee Tool" make a selection and feather at an amount of 35. After the selection is feather it should look like the below image. Inverse the selection, hit delete on your keyboard and turn the opacity down to about 85-90% depending on the photo and your done.
The Results!!!
More Tutorials: 
