Read my words: S M A L L!!!!!
I don't know what it is with pre-meds that they all like volunteering at the big hospital where they're relegated to observer status watching paint dry on the walls. At the smaller hospitals, because they don't have many volunteers and probably smaller staffs, you get to do things you'd never do at the big hospitals. At the clinic I volunteer at, I take vitals, clean wounds, bandage wounds after the doctor has seen them, go over charts with the nurses so they can explain things to me, talk to the patients in their rooms if I want. At the big hospital, I'd be making charts and changing sheets all day.
Also, at the small hospital, since there aren't many of us, I'm on the first-name basis with the doctors (well, they call me by the first name. I always call them Dr. so and so) and they let me shadow from time to time. It's great because I get my volunteering and my shadowing in in one shift instead of having to find someone to shadow at another time.