pretty impressive shadow art by Niloy J. Mitra and Mark Pauly. The film produced "Silhouettes of Jazz" was one of the three nominees for the Best in Show Award of the SIGGRAPH 2009 Computer Animation Festival.
I spotted one of Luke Jerram's 30 pianos, but was too shy to play. Pianos occur across London as part of an interactive art project to challenge people to come out of their urban insularity and also to provide some summertime music.
Eric W. Sanderson's Mannahatta Project, an exhaustive study and recreation of the Manhattan ecosystem circa 1609 (the year of Henry Hudson's arrival in Mannahatta), as an exhibition at the Museum of the City of New York.