First off you need to cut out the everything you don't want. You want to delete the objects in the background. The person(s) should be on its own layer. You can use the magic wand or the polygon lasso to do this. In this case it was a white background so there is little work that needs to be done. Now take all of the exposed skin on the person and color it black. You can also if you want go to image>adjustments>levels and bring the slider closer together and also make the skin darker. This will give you an effect like the U2 video.

Go to image>mode> hue/saturation and desaturate the people totally.

Now pick a color for the background (I used #a1c942). Make a new layer and just paint-bucket the whole layer.

Then duplicate background layer. Make it the top layer and select the non-empty space on the person(s) layer. Click on the mask button in the layer pallette. Set that layer to overlay. Duplicate the layer. (Hint: to add more punch make these two overlay layers a shade lighter.)

 

 

If there is a floor to your art follow this for a reflection. If your person takes up the bottom, your done.

Reflection:
Duplicate the peoples/objects layer. Go to edit>transform> flip vertical. Align the bottom of the flip with the bottom of the people. Make this reflected layer just on solid black color. Make a mask of this reflection. Pick the gradient tool and set the color palette to black and white. Make the gradient so as the reflection goes on the image gets fade out.

Discuss the Adobe Photoshop tutorials on the forums. You can find the photoshop files to download there too.