Check out this
post from Opus Research:

iPhone may be a tour-de-force for the touchscreen, but it’s inexplicably
odd to introduce a new smartphone with so few speech-based features. I
can hardly express how profoundly disappointed I am that this shiny, new
thing – the first must-have product since Nintendo’s Wii – has less
voice processing than Tickle-Me Elmo.

(from: iPhone
Lacks Conversational Aspects)

The point of the whole essay that stuck with me is the incongruence
between offering a product that requires 100% visual focus and that as
often as not will be used while driving a car." As he says: "With
all the attention focused on the fancy, new screen and multi-touch
controls, I can only imagine what the safety implications are for in-car
use."