Yarn bombing, also known as guerrilla knitting, is a type of street art or graffiti using items made from yarn - whether knitted, crocheted, or made into pom-poms.

BBC: Left Lion in Nottingham is 'yarn bombed'

Meanwhile, over the past decade or so, a concentration of cutting-edge galleries - featuring everything from SoCal's native lowbrow street and graffiti artists to Japanese pop-art imports - has reclaimed an industrial area on Culver's eastern edge, creating an arts district to rival New York's Chelsea neighbourhood.

BBC: Culver City, ready for its close-up

Cairo has suddenly emerged as the street art capital of the region, and its graffiti scene one that primarily started with hastily scrawled slogans calling for the overthrow of the Mubarak regime has evolved into one characterized by well-crafted motifs, both aesthetic and politically provocative.

FORBES: For Egypt's Revolution, The Writing (And The Drawing And the Photographs) Is On The Walls

That first effort was self-consciously hip, a place to hang, chat and read about graffiti "art" and South African street styles.

FORBES: Digital denim

Gabriel Schoenberg, CEO of Graffiti Tours New York, called Five Pointz one of the most significant street art establishments in the world.

BBC: Urban art attracts tourists