That's really neat, but these things never take everything into account.
For instance, my 2 blue-eyed parents have 2 blue-eyed DD's and 1 w/ hazel eyes. This is supposedly impossible.
But if you look closely, my eyes and my mother's eye both have a ring around the outer edge. This ring is hazel, and it is the color of my sister's eyes.
This calculator also does not take hazel into account at all. I'm sure it'll work for most people, but our genes are more complicated than this.
Thanks for the link!