Jim Stogdill and I had a conversation a week ago about the new iPhone 2.2 firmware that includes walking directions as well as similar projects in the space. In my Where2.0 Report I talked about the convergence of mobile devices and the effect on multi-modal routing: your phone changing from auto to walking to metro directions based on your context. However, I didn't go in-depth on example projects and services.
Jim posted my notes of our discussion on O'Reilly Radar. So check them out there. It's just an overview, but let me know if I missed an interesting project or story about open-data (or lack of).