I just got this phone and everything works pretty well but I can't get the voice dialer to work consistently. After it has been turned off it works once, and it seems to work through my Bluetooth head set but not when I try to speak into it directly.
Also, I am wondering if I need some kind of virus protection for the phone.
Try going to the market and downloading Vlingo. It's a better voice dialer and has some other options that you might like. It's free so there will be an ad pop up after you use it, but it is pretty good.