Answer:
I fill a room but take no space.
Without a bridle or a saddle across a thing I ride a-straddle. And those I ride by help of me though almost blind are made to see.
I am the place to turn to when nature calls. What am I?
So simple, that I can only point. Yet I guide men all over the world.
Though not a plant I have leaves. though not a beast I have spine. Though many wouldn't need me I am more valuable than wine.
How can you tell when a mummy has a cold?