I'd go for the D500. The Sharp GX32 has a killer screen and was by far the best camera phone of its time, but its time has long passed. It doesn't support mp3 ringtones (despite having an mp3 player), the bluetooth is restricted and the UI is nothing to boast about. It does have 850 though, something the D500 is lacking (it'll only be a problem if you're using Cingular).
