I made this one for the blenderguru Christmas contest.
Love to receive comments.
Very nice man. Busy scene you got here. Nice shadows under the desk, everything looks believable.
Nice idea and very realistic materials. The only thing i have to critique is the perspective of your background image compared to the perspective of your modelled stuff. Try this Addon: http://www.blendernation.com/2012/01/23/blam-geometry-camera-matching-add-on/ it will help you find the right perspective and camera settings.
He thanks.
@ beCoarse : useful tip you give there , I try it definitely. thanks.