This. Great summary!
I currently volunteer in the ED @ MGH and I love it. First, they treat us (volunteers) right. Free meal and free parking, so you don't have to worry about losing money when volunteering. Second, as mentioned, if you express an interest in patient contact, you'll get it. I truly think that volunteering in the ED is the way to go as a pre-med. You get to transport patients, provide them with friendly bedside visits, deliver meals, interact with nurses and physicians and, if you're a people person, gain key insight on the patient/nurse/physician triad. You also will toughen up: you will see blood, vomit, hear people puking and in pain, smell the worst smells imaginable and deal with transporting drunks/*******s. The flipside is that your visits to patients can really have an impact on their day. I've had nurses come up to me and tell me that patients were beaming after I left. Now, that may be my stunning good looks, or it may just be the fact that I'm someone not in scrubs or a white coat that wants to talk to them.
In terms of research, contact PIs directly, and network through any physicians you have shadowed/volunteered with in the past. I got my gig through networking and my willingness to work 20-30 hours a week free of charge. Also, they will be much more willing to take you in if you can give them a long term commitment. I've been at my lab for over half a year and I'm still being trained in new techniques. Nothing sucks more than to have someone finally get trained than leave. Some PIs will refuse to recommend you if this happens. Just be honest and upfront about your time commitment, have a willingness to work hard for no pay, and everything will work out. Research is awesome, especially once you're trained up. You'll have the opportunity to present ideas to physicians on a rather equal playing field, which is always nice.
Good luck.