Processing mono came up in the silvery sea thread so I thought I would present one of my own and discuss what I did with it. The original color image was processed with Nikon Capture NX-2 and the photo was taken with a Nikon P7100 point and shoot.
Here is the original color image.
I then used FastStone to convert it to greyscale
That seemed a bit flat so I reduced brightness, used the shadow slider and increased contrast to make it crisper.