I would run a fitness studio for adolescent/teenage girls. We'd offer all sorts of fitness classes based around hip-hop, kick-boxing and dance cardio. Sessions would only be a half-hour, followed by a 30 min. peer-run mini-workshop on lifestyle issues: body issues, relationships (parents/boyfriends/girlfriends), peer pressure, drugs, bullying, sex. Openess and confidentiality would be the cornerstones. Then I'd take the program into after-4 co-curriculars at schools.
The whole concept would be based on the massive, sometimes seemingly insurmountable challenges that girls 10-18 'ish experience. It would be be built on a system of peer support combined with guidance from trusted, knowledgable and trustWORTHY adult experts. No lectures, no absolutes...just lots of good information and support. It would be funky and cool enough that it wouldn't be geeky to participate. Every quarter or twice a year, we'd bring in a "celebrity" speaker.....to reinforce what we'd been communicating. High school athletic stars, big-name celebs (when and wherever possible), local teen over-achievers, kids who had overcome huge life challenges, etc.
Not that I've thought about it at all.