war-chalking

[play on war-driving; the first syllable has since been reinterpreted as an acronym for "wireless access revolution"] The practice of using chalk marks similar to hobo signs to indicate the nearby presence of a wireless Internet access point, a boon to strolling hackers with laptops. The concept was first floated in early 2002 and was instantly seized upon with cries of glee by hackers all over the portions of the world urbanized enough to have sidewalks and access points. The process rather recalls the explosive spread of heraldry in the medieval Europe of the 1120s. There is a site that explains the symbology;.