I love this interview with author and horse trainer Alexandra Kurland about how she uses clicker training with horses. I know people who think the Parelli method of Natural Horsemanship is great, but when I viewed the training DVDs for it I saw inconsistencies in cueing and cues that were actually slightly aversive. It's not awful, but it's not as good as clicker training in my humble opinion. I beg anyone involved with horses and ponies to learn about clicker training. It's non-coercive, effective, and fun for the horse. That's my kind of training!
Clicker Training in the Equine World: An Interview with Alexandra Kurland