We checked out Os Gêmeos, twin brothers Otavio and Gustavo Pandolfo, painting a huge mural down at Bowery & Houston. They've done a few other pieces here in NYC before. Read a bit about the twins here and here.
This wall has a rich history of graffiti art. Last year, a group of organizations commissioned a recreation of a Keith Haring piece that used to live on the same spot way back in 1982. It was a tribute for what would have been his 50th birthday.