War Walking, is similar to WarDialing and WarDriving. Except using feet instead of modems, or wheels. Basicaly, take a really light notebook, a PVC pipe yagi that you made, and wander around town while the tourists look at you like you're nuts. Which of course, you are.
War Chalking is a movement to "tag" an area covered by wireless "hot spots". It's a cheap, easy way to indicate public wireless 802.11 access using chalk. "Mark-up" curbs, walls or sidewalks - wherever you find wireless access.
Blackbelt Jones explains that War Chalking is a pun on WarWalking - itself derived from WarDriving which has it's roots in WarDialing.
War Chalking updates hobo sign language for the 21st century wireless geek.
Get your wa-was out!