First off, I totally agree about the stroller thing that Bookgrl said. I saw those little backpack ones a lot in Dublin.
I admit that I'm someone who used to think poorly about kids on leashes. Then, I was listening to the radio one day and the DJ was talking about taking his kid to Disney and needed to get a leash for him. His kid was a bolter and since they were going to such a busy place, they had to ensure his safety. No leash and he would be lost. They had other kids that didn't need this safety device when they were his age, but they recognized this about him. He doesn't wear it all the time, but they know his limits. I changed my mind about them as soon as I heard that. Your job is to keep your child safe and if that's what it takes, then so be it. Screw what other people think!