I bought a book recently called Darkroom to Digital (Eddie Ephraums very good). Basically it is one mans journey in making the transistion to Digital B+W photography. The book has many examples of toning which are of course much better than this effort, but I was quite taken inspired by them so decided to have a quick go myself. I think I will continue to investigate this technique.

Firstly apply the normal curve adjustments to suit and then convert the image to grayscale and on to duotone. Add the pantone 156c or 157c as the second ink and play around with the curves until you get a nice result. Convert back to RGB and add some noise (I used a radius of 2.45) finally USM.