i particularly liked the sci-fi look that these images had (or i just watched too many sci-fi movies for my own good). in both cases i added some split-toning which actually didn't change it too much as the pictures were already taken at sunset where you get the nice cool blue shadows and bright warm highlights.
i used the incredibly flexible 18-135mm kit lens for both shots.
the really strong out of focus effect is a combination of (as you may already know) a very wide open aperture (f 5.6, the largest on this lens) and a long focal length (100mm here I think). this means the rest of the image not in focus will be very efficiently blurred out as you can see.