My golden retriever does, at birds, squirrels, aeroplanes etc. It's fair to say, though, that he only looks up if something else, e.g. a noise, first captures his attention.
Look up what? An old friend? A dictionary? Sorry, just fooling. Seriously, yes they can look up. Our dog (sadly passed away) used to look upwards at us from the floor with loving eyes.
i have pondered this before, it seems to me that dogs, if you think about it are already looking up, in comparison, if we are on all fours we would, in a normal neck position, be looking at the floor, if we looked up to see forward it would be as though we were leaning our heads back as if looking up. for a dog to be looking up, it is that he is actually bending his head right over his back, if you can follow my clumsy explanation!
I thought it was something to do with they can move their heads to look upwards, but their eyeballs are not as mobile (yuk) and so have to move thier whole head; and not just look upwards with ther eyes as we can. Just my thoughts, not fact.