»In which we take a guided walk

ask.com now offers pedestrian directions as part of their mobile widget, and another (Flash-based) site offers excellent walking direcions through most of London.

Having walking directions available may prove a phenomenal application for mobile devices, and probably also a windfall for advertising. I would probably appreciate an expert-informed recommendation for a good café when walking around an unfamiliar city, and possibly also an advertising incentive. Having the directions, and making them rock-solid, is a great start towards even better local, targeted advertising.