[Newton]

Quick is not good man .. The best way is to place the image on a new layer above the background, then make the background/or previous layer something like lime green and as vibrant as you can bear. Go to the layer with the image in it and start using the paintbrush on 5 pixel soft edge and the mode drop down set to Clear .. then proceed to trace around the edge of the image carefully, changing the brush widths as required.Just remove the rest of the background with either the magic wand or with the marquee tool/paintbrush of larger size to leave just the image. Once it is all done you will be left with an image you can place on any background.