Thanks for your comments guys, if there's one thing I've noticed about my efforts with Photoshop recently is that I tend to go for a lot of contrast in my pictures. Not everyones cup of tea I know and I think I need to learn to judge where and when to use it.
As far as the B&W conversion:
First thing was to open the channel mixer adjustment layer, tick the monochrome box and set the RGB values to 33,33,34 respectively.
To boost the contrast a little I ran a very soft 600px burn brush over the image with the exposure set to 8px.
The next step was to open a hue/saturation adjustment layer
between the image layer and the channel mixer layer (so that it's applied to the image). This is where you can play a bit with the saturation. I boosted the blues by about 40% and reduced the reds by about 30%. Depending on whether your image is predominantly light or dark will determine what works best. It's just a case of trial and error.
Once you're happy - flattern the image and you're done. However I added a very slight sepia tone by opening and hue/saturation layer, selecting the colourize box and entering 43 in the hue box. The overall opacity of this layer was reduced to 40%.
Flattern everything again and away you go.
It was interesting that Manta said he looked like an extra from Lock Stock, this picture was taken in Borough Market in Southwark, London where most of Lock Stock & Two Smoking Barrels was filmed.