Ugh, that's TERRIBLE! Believe me, I feel your pain. I had a kidney stone back in the fall of '06. I was in bed for a few hours dealing with the throbbing pain before I finally went to the doctor's office. It was small enough that I was able to pass it on my own, so they gave me Vicadin and sent me on my way. To people who have never had one before, I tell them to imagine being punched in the kidney while being kicked in the crotch every single time your heart beats. I imagine it's even worse for you if you have a bigger stone. God, I'm shaking just thinking about that again.
Also, I know a woman who has two children and had three kidney stones. She told me she'd take the pains of child birth over kidney stones any day.