Can this flash damage my camera?

A friend offered to give me a Vivitar 2000 external flash to use with my Canon Digital Rebel XT.  I read up a little on it, and found a couple forums stating that there was a voltage discrepancy and that it could damage my camera.  But others said you could somehow compensate for that and it would be fine.  But I didn't understand their explanations of how to do compensate.

Bottom line, should I use this flash or not?