It seems that the Term warchalking / wardriving may be misunderstood in some cases. Since I'm writing on a book about wireless lans, I found a site called www.wardrivingisnotacrime.com, which I find quite useful.
Please note that there are different people with different meanings of wardriving or warchalking. If your opinion differs, please let me know, maybe I can use it for my book.

By the way: If you did some funny or tricky things with wireless lan and the empeg, please let me know

regards,
Rolf