There are tons of things you can do with miniatures - lots of driving options - from around the house to breed shows to combined driving and American Driving Society shows, in hand jumping, in hand obstacle, driving obstacle, liberty, halter, showmanship, color classes, costume, little kids leadline and riding, therapy work, backpacking on hikes - really now, what can't they do? With my riding horses I typically went to an open show and did 4 classes - Western pleasure, horsemanship, showmanship and halter. I have a LOT more classes to compete in at a miniature horse show!
My Mini's also do tricks. My stallion will sit like a dog, kneel, lie down, and rear on command as well as being a great cart horse, in hand jumper, and in hand trail horse. Recently his biggest job around here has been dragging my arena for me, he has saved me a bundle since I don't have to buy a four wheeler to drag with now.