Art + Media House, by a group of kids who took a class as part of DC's Summer Youth program. I spoke to one of the teachers a few weeks ago, he said the kids went around and asked people what they thought of the neighborhood, and they used their photos and quotes for the mural.
Pretty cool idea. DCist also used a photo of it as one of their Photos of the Day.
It's on Kenyon between 11th and 13th St NW around the Harriet Tubman Elementary School fields.