Yellow Arrow was a public art project created by Christopher Allen, Brian House, and Jesse Shapins that was active from 2004 to 2006. The project is an important example of locative media and mobile phone art and draws concepts from psychogeography. Yellow Arrow stickers were obtained from the project website and placed anywhere in the public realm. When encountering a sticker on the street, one could send the unique code printed on it as a text message to the project phone number. Moments later a message would be received that was left by the person who placed the sticker.