I believe that for a student to really learn something, it must be experienced. For this reason, I put together trips abroad every other year. I have led 3 trips to Costa Rica, 1 trip to Australia, and I am working on a trip to Alaska for 2005.
These trips center around high adventure including white water rafting, horseback riding, hiking, repelling, fishing, surfing, and many more. I travel with a company called Joshua Expeditions, a non-profit student trip organization. The trips are "all inclusive" in so far as they include airfare, hotels, all meals, and all activities for one low price.
I also try to build in a service component in each of my trips. It is fine to enjoy and learn about the natural environment, but our boys need to know how to give something back as well (and they do get service hours for it).