Google Books = Free Books

So Google Books has started putting PDFs of public domain books up on the web, so that anyone can download them. One of the books that I found was one of my favorites - Flatland by Edwin Abbott Abbott. It's the journey of a two dimensional square into line-land, point-land, and 3 dimensional space. Not a long read, but it's nicely written, and it's a great way to explain dimensions to a child, and to get them thinking :)