An interesting list of quotes about mathematics, as compiled by readers of the Freakonomics blog.
Here's one that's new to me and that resonates with me at the moment, having spent the afternoon creating a document which is essentially a list of facts, to which I'll add the proofs later. It's attributed to Poincare, although a bit of googling seems to indicate he said it about science, not mathematics.
"Math is built with facts as a house is built with bricks, but a collection of facts cannot be called mathematics anymore than a pile of bricks can be called a house."
What I have now is a pile of bricks. I have the mortar that holds them together, but it's not in the same place.
You'll also find the text of the poem which begins "I’m sure that I will always be a lonely number like root three", featured in Harold and Kumar Escape From Guantanamo Bay.