Paint it black.

DustTag is an iPhone application designed for graffiti writers that visualizes the motion involved in the creation of a tag. It is basically the iPhone version of Evan Roth his Graffiti Analysis tool, just with a little less bells and whistles but some typical iPhone features. You can write tags on the iPhone and upload them as .gml files (Graffiti Markup Language) to the 000000book.com website. Evan designed this app together with Chris Sugrue. Support them and buy this app for just $1.99!