I ran into this problem at one point, and got Flite (festival lite) text to speech engine running on iPhone. I recently made an API class for it. I tried to make it easy (and free) to add to new and existing projects. It can be downloaded at here.
I'm doing some research on the feasibility of an iPhone application, and can't find any indication in Apple's documentation that an iPhone app can read the call history of the phone, specifically the number called, when, and the duration... I …