added walking directions to its Google Maps product today. The walking directions ignore one-way streets and Google Maps tries to give pedestrians the most direct and flat route possible. As Google itself acknowledges, the Maps database does not currently have a lot of information about sidewalks, pedestrian bridges, or if a specific street is simply too busy to cross. They are, however, working on improving these aspects of their maps.Google
Walking directions are available everywhere Google offers driving directions.
Google will only allow users to chose the walking options for routes shorter than 6.2 miles (or 10 kilometers). Because of the limitations in its database, it is calling the walking directions a 'beta' products, but, of course, that doesn't mean much when it comes to Google products.
Currently, Google is the only mapping service that offers walking directions. Ask.com used to offer walking directions, but that feature went away when Ask migrated away from its own mapping platform to Microsoft's Virtual Earth three weeks ago.
While Microsoft's Virtual Earth updated its imagery with another major (14 terabyte) update today, it's routing functions have not seen any updates lately. In terms of overall functionality and user interface design, it is very much on par with Google Maps (and, in terms of its imagery, often much better than Google Maps). However, it never quite achieved the popularity of Google Maps.
The walking directions are currently only available through the web version of Google Maps. As of now, you can not chose them in the iPhone Maps application, though that would obviously be a very useful feature to add and hopefully Apple and Google will do so soon.