A grassroots organization is stepping up its efforts to combat harassment on the streets, buses and trains.For years, Holla Back NYC has been encouraging women to snap pictures of cat callers and harassers, and post the photos on the group's site. Now the founders want to make that process easier. They are planning to launch an iPhone application this summer that will immediately send the photo and other information to a database. From there, Holla Back will compile data that organizers hope will encourage greater enforcement of anti-harassment laws in the city. Less