Here are some comments from my friend Marisa who participated in VOSH Nicaragua this past winter break and VOSH Thailand last year as a first year.
------------------
VOSH is an awesome experience. We got to work with great doctors, opticians and technicians, meet students from other schools, make friends from other countries, explore a different culture, and improve people's lives. Your clinical skills also become so much better from the experience. As a current second year, you're not exposed to regular patients much, and in school, you work with your classmates who know what you're doing with your exam procedures.
Out in VOSH, you have to not only be able to do an exam as accurate as possible--because your patient depends on it--but you also have to know to communicate with them in some way despite not being able to speak the same language sometimes (for Vosh Thailand, I didn't know how to speak Thai but sign language/facial expressions go a long way
and my old high school Spanish skills got so much better after Vosh Nicaragua). Whats great also is that you have colleagues and other doctors right next to you if you have questions. It really puts one's life in perspective when you experience what a third-world country is like. I've learned so much from my patients and from my classmates/doctors whom I went on VOSH trips with.
How to become involved in VOSH and how VOSH trips are planned varies from school to school. Since UCBSO doesn't support VOSH at all (grrr...my pet peeve about this school), the Vosh trips are organized by the students themselves and we have a point system (based on volunteer hours and what year in school you are in) on who gets to go on VOSH. If you're really interested in going though, you can even go in your first year if you work at it. We fund our own trips, but some schools support VOSH and fund them too.
In planning we link up either with a VOSH organization or with doctors from that country. Each trip is different (days, hours work, etc.) based on who organizes it. I have a detailed list of recommended equipments to buy for vosh but it vary from school to school and trip to trip too (and generally you need that equipment anyway for school so it's not a huge extra equipment expense).
Its a wonderful fulfilling experience, so if you get a chance to go, definitely do it. Hope that answered some questions!