That's some fun 3d stuff. Most are pretty damn solid.
Like the room/table image.
What programs did you use?
my sketches here... http://conceptart.org/forums/showthread.php?t=92997
www.sevans.co.nz , visit them or a puppy dies!
The table piece was made with 3ds Max, Photoshop and Fusion.
I'd love to draw more and post my rubbish sketches here