Graffiti Analysis 2.0: Digital Blackbook from Evan Roth on Vimeo.

This Graffiti Analysis project is wildly impressive.  Via QBN

Graffiti Analysis is an extensive ongoing study in the motion of graffiti. Custom software designed for graffiti writers creates visualizations of the often unseen motion involved in the creation of a tag. Motion data is recorded, analyzed and archived in a free and open database, where writers can share analytical representations of their hand styles