Yeah, I could do that or MyFitnessPal - I guess I'm not sure on the ethics. People themselves want to share their photos, but is it okay to reach them through someone else's fitness site? Hacker News and non-fitness-related sites seemed kosher, but I'm not sure about those... advice?

I'm trying to think of ways to make it a win-win for everyone - maybe promote the site/product/trainer that helped a person, but in a way so that the site isn't selling a particular product. Ideas welcome.