Very few, if any, cities remain untouched by the street art craze; Sydney is no exception. No longer a form of rebellion, street art is now often created as part of an urban beautification scheme or to promote tourism. This exciting form of artistic expression is becoming increasingly popular and is popping up in cities worldwide. And no wonder. Many millennia ago, the impulse to leave our mark on our environment was set in stone (excuse the pun). That is to say, cave drawings date back 44,000 years in Indonesia, and Spain believes it has cave art dating as far back as 64,000 years.