I checked and re-checked, and I think I have it hooked up right. I have the DS18B20Z, with the SOIC package, so I have GND on pin 5, the PIC's 5V on pin3, and the one wire line on pin 4. I have a 4.7k ohm res pulling the one wire line up to 5V. The one wire line is connected to PIC portB.0. I bought 2 sensors from digikey, and I tried both of them, the same thing happens with each one. I power up the board, then in hyperterminal I see:

Power Up
start convert

and then nothing else, but there is lots of activity on the one wire line.