Besides, the creature I've always called a daddy long legs isn't even a true spider (10 legs and no silk, IIRC).

S'right, Arinida, IIRC.

DAMN that's nasty. I had a friend that got bit by one on his right hand. He said he woke up the next morning with his arm paralysed and a nasty black streak up his arm and halfway accross his chest. Doc said if it had been on his left side and that much closer to his heart it might have killed him.

It is a colloquial tag in many places. In Sud America there is a mosquito like creature that is referred to as "daddy long legs" that is fairly dangerous.