Black Hole Physics for Non Math Types

I got this info from a reliable source, though I don't remember if it was Nova or something on the History Channel: 

To understand the density of a black hole, imagine the earth at its current weight and size.  Now imagine it squeezed down to the size of a golf ball, but keep the weight the same.  The density would be so high the gravitational field would suck everything into it, even light. Et voila!

If it's too upsetting, just don't imagine it with any of the earth's creatures being involved.

Here's a story about the new baby black hole!