Any ideas for making money this summer?

My neighbor and I are looking for ways to make money this summer. Please don't say lemonade stands because we are both 13 years old. We both want to have a business together. He is good at mowing lawns and I am a great babysitter. We don't know what to do. We both want to do the same job when we are working. And when we do find a job to do,how do we advertise it in our neighborhood?