New walking directions feature in Google

I was checking some driving directions in Google and noticed they have added a beta "Walking" link. I played around with it and it's pretty decent from what I see so far. It will map the shortest distance between two points instead of the fastest car route. It will also estimate the time it will take you to walk it. I did check how long it would take to walk from SC to IA, but it doesn't give the walking directions option for a trip that far. :-) You can play with it yourself here. Not sure what the distance limit for walking directions is, but after playing with it a little, it seems it is about 6 miles.