Make a list of things that can be done for others such as mowing lawn, rake leaves, washing dishes, sweeping front porch, take out trash, shovel snow, dust, or any basic household chore. Then set up teams (of at least 3 but no more than 6) and have them go to various houses and do things for them. It is a good idea to have an adult helping them since they may be shy. When we did it, we also took buggies into the grocery store and helped someone carry out their groceries. Some people were really surprised by this. We sent a camera along with each team so they had proof the stuff had been done. They also came back with stories of people that did not want them to do stuff and people that were over joyed by kids doing something for someone else. Afterwards they came back and the winning team got pizza.
This is an idea that I got from a youth group in Midland Texas. I have no clue where they got it but I really liked the idea and wanted to share it with you.