Hello Tark--yes YIKES to those leg cramps. I've gotten those leg cramps too--either from stretching my leg during sleep or during the day trying to get in some weird position to reach for something or bending my leg in some funky position. Right before I do it, I know what's going to happen but it's too late by then.
I know exactly what you mean! The next time you begin to cramp up, grab your calf with both hands and squeeze the hell (with your thumbs, right on the knot of the cramp) out of the muscle! What you're doing is preventing the calf muscle from tightening up, and keep squeezing for a few minutes. When you eventually let go, stand up and stretch the calf muscle. It'll probably be painful, but it helps in keeping the muscle from cramping up again soon afterwards. I've used this technique the last two times I've cramped up, and it works!