Nice work blinn. I think the second image with the bear needs some work with the lighting and shadows though. It might be better to select one primary light and use that for your shadows as at the moment they seem to be in different directions. For instance, the outer right side of the box looks like it's lit yet there's shadows. The bear is also casting a shadow behind it, that's another direction.

Also, unless you have a light shining directly into the box and from a low level i'd suggest ambient light in the box falling off before it reaches the roof, just looks a little to even to me. Other that that, very nicely done.

Just one other thing about the first image of the house. Perhaps you can see better if you have the original image used for the sky but it looks like the sun is above and behind the house? So maybe the front face should be in some shadow. It would make things look a lot more atmospheric. For such a cloudy sky the house looks too bright.