Best Line in Anathem

"Do you need transportation?  Tools?  Stuff?"

"Our opponent is an alien starship packed with atomic bombs," I said.  "We have a protractor."

You might think that's a spoiler, but it's not really.

Second Runner Up:

"Let's buy a sextant, then", suggested Fraa Jad.

"Those have not been made in four thousand years," I told him.

"Let's build one then."

"I have no idea of all the parts and whatnot that go into a sextant."

He found this amusing.  "Neither do I.  I was assuming we would design it from first principles."

--Bob, still trying to figure out what the heck happened to Fraa Jad