I would recommend getting him a backpack harness. We have one shaped like a monkey that my kids love. If you have time for him to walk (you may want to allow more time for errands when he firsts starts walking) tell him, you can walk wearing your backpack, but if you don't listen or touch stuff, you are going to have to get in the stroller. My son was much more cooperative when he walked, plus I found it tired him out so he took a better nap too. I also found that he would walk for about 20 minutes then ask to ride because his little legs would get tired. Also, to encourage him to stay in the stroller make sure he has some toys and a snack and drink to keep him occupied. I keep a box full of easy snacks (pretzels, crackers, raisins, etc in the back of my car along with a box of snack size bags) so I can give my kids a snack while I run errands. I am not sure what type of stroller your using, but with ours, my son can't really get out without help, since he sits low to the ground it is hard for him to climb out, so I guess he has less opportunity. Also, he is old enough for their to be consequences. If you have warned him to stay put and he doesn't, you can always find a place to give him a time out or take away a priviledge (we take away his bike or sometimes tv) for the rest of the day. That has been effective for us. Our son could care less about time outs, but hates to lose his bike. The trick with that is finding something that your child really likes. Good luck. This is a tough age, but the threes are so much easier:)