As I suspected, the lack of voice dialing on the iPhone is going to be tackled by third-party developers. Here’s the first entry into the area that I’ve found: iSpeak.
“An unlearned carpenter of my acquaintance once said in my hearing: "There is very little difference between one man and another; but what little difference there is, is very important." This seems to me to go to the root of the matter.” <William James>