Jeremy Wood of GPS Drawing has a large canvas: the world. He uses Global Positioning System (GPS) technology to record and render his movement into a drawing on a map.
I'm particularly fond of this 11.2 km (about 7 mi.) long GPS elephant in the streets of Brighton and Hove, UK: Link - via Forum, original post by lilrawker
http://www.archinet.cn/amy/weekly/20060312-2.jpg