Photo: (Mariah's Challenge) Leo McCarthy is offering teens money not to drink. McCarthy lost his 14-year-old daughter, Mariah, five years ago, when a 20-year-old drunk driver hit her and two friends as they walked down the sidewalk in Butte, Montana. But he turned tragedy into triumph when, at Mariah's funeral, he offered teens this challenge: "If you stick with me for four years -- don't use alcohol, don't use illicit drugs, but give back to your community, work with your parents, and talk to your parents, I'll be there with a bunch of other...