I do quite a bit of positive reinforcement training which the pups respond to very well. However, when we are on a walk and they don't pay attention I took a lesson from the Dog Whisperer. He suggested to walk with a loose leash so they are relaxed and when they stop paying attention to you and to another animal or person to tug on the leash and let out a short "tss" sound through your teeth. It has worked wonders with both of them. I occassionally have to do it a few times in a row, but they are quickly learning that if they don't pay attention to me the walk will not be as fun. I also can make the sound now related to other things (barking, etc) and they stop.
As for the humping behavior...most people on here probably wouldn't agree with me on this one, but since they do act like they are in another world and I have tried many other things that didn't work, I now give them a light tap on the behind. A light spanking (I don't hit them hard) and that tap seems to be enough to get their attention and get my "NO" across because they stop immediantly fater I say no. After doing that a couple of times they've stopped that behavior...at least while we're around. We're planning on getting both of them fixed next month too so hopefully that will help that problem a little more.
Oh an I tried the coins in the can for all of these things and they could have cared less that I was making noise...they just get louder when I do it...
Good luck with your training. My boys still aren't angels, but they're learning. I'm sure your little one will too.