I read threads like this, and wonder if I've just been unlucky, or if people exaggerate a lot (I'll just go ahead and assume the latter, if only because it will help me sleep better at night).
The closest I've ever had to this phenomenom would be my first gf, but she never once "squirted". She would get extremely wet when she was aroused (which was still hot as hell), but no fluid ever spurted out of her.
Some girls can not suirt even with a g-spot orgasm. I have been with one girl who squirted our first time fucking. A couple of x-girlfriends did not know they could squirt. I tried and it took a couple of trys, but they finally squirted and then it continued. Its like their body had to be trained first.
Full body massages can help. Not lying, try it out.