Ask HN: What first aid classes would you recommend?

Yesterday's attacks in Boston highlighted just how much civilian first responders can help in a mass injury situation. As a lifeguard for four years, I went through a lot of first aid drills and training a few summers ago. Recently, I took an American Red Cross first aid refresher course and found their curriculum to be a bit lacking. It touched on a number of subjects very briefly without providing much depth for someone who might be learning CPR for the first time. Are there other courses that do a better job of providing both comprehensive and also in-depth first aid training?