I was just reading an article on GigaOM detailing the grown of cell phone navigation. It turns out that ComScore has released data showing that more and more mobile users are utilizing mapping features on their cellphones. I know I use Google Maps regularly and have a few friends who are die hard TeleNav fans. These tools have saved me quite a few times when I was hopelessly lost.
The problem with current navigation is that the price is a bit too high for casual users. If you use TeleNav every day it is worth $10. On the other hand if you don’t you would probably be better off just purchasing a $150-200 standalone GPS with a much more intuitive touchscreen.