With its ability to make boring cellphone photos look "vintage" and "artsy", Instagram has exploded worldwide. Derided by its detractors as a tool for making bad photos worse, we take an alternate view and argue that Instagram is the greatest thing ever to happen to photography. Its simple filters and social networking features are training cellphone photographers everywhere to think creatively about their photos. Plus, the app is turning its worldwide user base into an army of photojournalists capturing striking images of the people and events around them. As the old photography adage goes, "The best camera is the one you have with you."