a great article about a mysterious orange line of paint that had snaked it's way across Manhattan a few years back. Turns out this line was an immense graffiti tag by an artist named Momo which actually spelled out his name.
As you can see on the map here, the mysterious Momo traced his name onto the city's grid using a bike that was surreptitiously dripping paint as he wove an 8 mile path from West to East. Since it was originally done in 2006 the line has gone mainly unnoticed until the blog Best Roof Talk Ever posted about it last month.
The most fascinating mind-bender about this biggest tag ever is, of course, the fact that the tag cannot all be viewed at once. The line of paint is relatively thin and nearly worn out in some spots. But, as in all art, it's the thought that counts.