you take a toothbrush handle, heat it up till it's soft, then press it into the tamper proof screw head.
Thanks a lot for the tip, BigB!, I'll keep that in mind.
Yeah, I've got a few of them sets, each having a different selection of bits.
One bit I really find annoying is the smallest "snake-eyes" screw bit, if you happen to turn the driver with too much force trying to initially get the screw to loosen, you can kiss that bit goodbye, I've snapped more of them bits than any other.
Our local automated toilet cubicles down town used them screws prolifically, all though it never stopped all the vandalism that used to occur on the weekends.