Mark Rinkel, 12, of Aurora, Colo, a seventh-grader at Challenge School in Denver, raised more than $16,000 through lemonade sales and Internet solicitations to purchase and train medical service dogs for his little brother and other children suffering from type I diabetes. When Mark's brother, Jason, was diagnosed with diabetes, their mother applied for a "diabetic alert dog" from an organization that trains dogs to detect abnormal blood sugar levels in diabetics. "When Jason was approved for a service dog," said Mark, "I wanted to help him get the dog, and take the burden off my mom by raising the $6,000 towards the cost of training a dog." Mark designed and built a unique lemonade stand, researched lemonade recipes, and recruited friends and community members to help him sell fresh-squeezed lemonade (along with a sugar-free option) and distribute diabetes-awareness flyers at community events last summer, often in 100-degree heat. Mark also spent many hours constructing a Web site to spread the word about diabetes and solicit donations. So far, he has raised enough money not only to train Jason's dog, but to provide dogs for other young diabetics as well. "I've had hundreds of e-mails from people who are struggling with the devastating effects of diabetes, who now know that a diabetic alert dog could save their life," said Mark. "I once felt very helpless. By volunteering, I stopped feeling helpless."