Even though there was a free app floating around for jailbroken iPhones for some time now, a more official version of Voice Dial for iPhone has made its way over to the App Store. No, the kindly developers did not leave it with a price tag of zero dollars, instead upping the ante quite a bit to attach an asking price of $25.
Not to be confused with iSpeak, Voice Dial for iPhone does exactly what you think it does. For each entry in your address book, you can tack on a voice recording. From there, you will be able to dial up that contact without having to fumble through a menu or do any sort of virtual dialing on the touchscreen. It’s unfortunate that it needs this training though.
If you feel inclined to drop 25 bucks on a voice dialing application, you can find it in the App Store. (Warning: link opens iTunes)