There are various little "hobbies" in emergency medicine, like wilderness medicine and international medicine. You don't really pay the bills with your hobby. You can volunteer in times of disaster and travel thousands of miles and ogle at the bad luck of survivers of hurricanes once every couple of years. Is there an advantage to doing an ER residency to prepare for this? I don't think necessarily.
Disaster medicine is more a function of effectively distributing resources. Being able to put in a chest tube isn't going to save thousands of peoples lives as much as guiding an army of volunteers. Public health seems like an even better marriage to me. I think family practice would be as good of a choice for a specialty.
In emergency medicine, we are good at resuscitation and using advanced imaging and laboratory methods to diagnose and rule out emergencies. We have a host of drugs we use to ease suffering and treat emergencies. One thing that you absolutely do not train for is effective resource utilization. Take away our nurses, our medications, and our imaging, and our cool toys, and we are no better than a family practice doctor in an emergency.
I don't know if there are fellowships, but what good would a fellowship be? I mean, you learn to manage disasters by managing disasters, not by sitting around a table talking about it before hand. How could a fellowship supply a consistent number of disaster opportunities for you to learn?
I'm picturing a very excited young resident showing up every day to an office with their bags packed, and praying daily for a "cool disaster" they can go manage (Shake head)
Having said that, here is ACEP's website with a link to some resources that might interest you:
http://www.acep.org/ACEPmembership.aspx?LinkIdentifier=id&id=40898&fid=826&Mo=No&taxid=112453
In my opinion, you should only go into emergency medicine if you intend to work in an ER. Otherwise, don't waste your time, or your residency directors resources. I knew enough med students who would hav given their left nut/ovary to get into ER, but couldn't, that it irritates me that people would want to go into ER without the primary objective of working in an ER. You are wasting a residency spot and decreasing the number of functioning ER physicians that we are so badly in need of. Hobbies are fine in addition to ER work, but you shouldn't generally hope that they are going to provide you with a consistent and viable career. Most people who spend 11 years on education want a CAREER, not a hobby.