We're always inspired by the people who use YouTube as a way to document how the other half lives, and Mark Horvath is a great example. As the founder of Invisible People. tv , a project that encourages homeless people across the United States to tell their stories on YouTube, he has sparked a discussion on the site about poverty and hunger. Mark's videos are a raw and real depiction of what it's like to live in a tent city, under an overpass, or within a cardboard box. Today,