Wow, I can honestly say I have never heard of "500." Interesting game, though. Does it have to be an increment of 100 when you throw, or can you just shout out a random "83" or something like that?
That must have been the nerd version...then you'd have to add in exponents, logrithms, and trigonometric ratios to make it really fun! Of course, they probably wouldn't be able to catch the ball in order to get the points.
Curball is a new one on me as well. Smear the queer I have heard of...never played it though since I knew I would get crushed.