For kitchens with less space, the foldable Kitchen Helper Kids» Step Stool Platform is a nice alternative children's kitchen stepping stool, since it can be folded flat for storage when not in use.
When our (now 9 - year - old daughter) was very little we had not yet discovered the Learning Tower (or the alternative for smaller kitchens, the foldable Guidecraft Kitchen Helper kids» kitchen step KitchenHelper kids» kitchen step kitchen step stool.)