I did a basic, then advanced EMT course. The basic taught me how to take a pretty good history and do a basic physical examination. The advanced taught me how to perform venipuncture, insert IV catheters, Intubate, collect and interpret ECG tracings, and treat cardiac and other emergencies.
I parlayed the EMT-IA certification into some good clinical exposure. At a free clinic that I volunteer at I am allowed to practice my full scope of training. So basically I draw a lot of blood, start and manage a lot of IV's, do 12 lead ECG's, give a lot of injections, among other things. When I shadowed physicians it usually ended up being a situation where I'd go see the patient first and get a history, do a brief exam and report to the doctor, then we'd both go in and I'd observe the rest.
My EMT-IA certification also helped put me in a postition where I got to lead a large scale vaccination campaign. The medical director at my clinic knew me and was familiar with my abilities so she let me plan the whole thing, recruit volunteers, and take them to the streets to give vaccines. I had about 40 undergrad students (some of them paramedics etc.) and we gave about 4,000 H1N1 immunizations to the homeless in the fall of 2009.
After that, I signed up as a volunteer medic with the US Navy and spent a summer aboard a hospital ship in Indonesia and East Timor. Basically doing all the same things I did at the free clinic.
This is why I always laugh when people say getting an EMT certification is a waste of time for pre-meds. I won't argue that it's a waste of time if all you want is the certification. No interview committee will care about the cert., but if you can use it to get some killer experiences, they will care about those. The way I see it, an advanced medical certification can open a lot of doors for patient contact and care.
SLC