Oh the little harnesses? I used to be totally against it, but when my kid was a toddler and constantly tried to wander off, no matter what I said, I finally caved and got her a cute little animal plushy one. As long as you aren't yanking or dragging them and have a stroller ready for when the little tots are tired, it's fine. It was really helpful when we went to Knott's Berry Farm and Universal Studios.
Contrary to popular belief You cannot watch them every minute and not every child is obedient or super understanding at that age.