attiny 85 and the ping sensor

hmm i guess i was miss informed about the 3 pwm pins @ code badly i was readinhg threw the fourms and found some ones post about the third digatal pin and i read that the pb2 pin anlog pin 1 could dubble as a digatal pin with out pwm but i read threw most of this http://arduino.cc/forum/index.php/topic,87517.0.html and could not find how this is done manged it on my own do you have to do some thing to the chip to make it a pwm pin or just program it to do so like normal ?

@fungus i figuer your limataions are end less with the programing and soft ware side of things but that greek to me at this point im begining to under stand what i can in my free time