I was looking for this feature on the 3gs but still unsure where/how to activate the turn-by-turn. I did a do directions (current location to said location) and I still had to click the next button for forward through it. I did see the gps blue dot moving but nothing else. I am working at the moment or I would mess with it more but any guidance on using the turn by turn would be helpful. I am thinking I have to purchase a GPS app (tomtom for example) to get it to work. I would mess with it on my way home from work but I decided to ride my motorcycle in today.
(I upgraded from 2g to 3gs, btw)