When Joshua Williams was 5 years old, his grandmother gave him $20 to spend on whatever he wanted. My mom and I were in the car on the way to church, and I was thinking about all the fun things I could buy," he says. But then, while waiting at a red light, he looked out the window and saw a homeless man begging for money. Joshua leaned forward and said he wanted to give the man the $20 so he could get a meal. "I suggested that we go buy the man some food," says his mom, Claudia McLean. "But Joshua pointed out, 'What if he doesn't like what we get him?' From that moment on, he was pestering me about how we could help more people." Soon, the family began cooking meals every Saturday to distribute to the homeless. Still, says Joshua, 11, "we only had so much food, and I knew people were still hungry." In 2007, Joshua and his mom established Joshua's Heart Foundation, which has since given away 400,000 pounds of food through a variety of initiatives. But the foundation's backpack program, which discreetly issues food-filled packs to needy schoolchildren before weekends, is closest to the seventh grader's heart. "When kids don't have to worry whether they'll have dinner that night, they can concentrate better, do better in school," he says. The program benefits 50 kids in two Miami-area schools, but Joshua hopes to expand it via corporate donations (Walmart has given $20,000). The foundation now has 700 volunteers, plus a Junior Advisory Board over which he presides. "When I look at the faces of the people we're helping and see how happy they are, that's my favorite moment," he says.