Buyer beware: Just because the Samsung SGH-x475 is a new flashy cool-looking phone, don't assume it has as good of features as older cheaper phones.
This phone has no capability for voice dialing. You can use the little button on the hands-free accessory to answer and end calls, and to do a redial of the last number you called, but that's it. If you want to call anyone else, you've got to flip it open and hunt around on the keypad.
My old unsophisticated Motorola C332 could voice-dial from names I had recorded into its phone book, and that feature was great while driving. I stupidly assumed that a newer model phone would at least have the features of older, cheaper phones. The problems with the Motorola were pathetic battery life and pathetically weak volume in the earpiece. But at least I didn't have to take my eyes off the road...