A collection of 100 essays on vaguely mathematics-related things. Makes for good train or bus reading as each essay is only a few pages and self-contained. On the other hand, the brevity of the essay tends to prevent them from getting into super interesting details, so it’s definitely light reading. A final note: don’t buy this on the Kindle. It lacks the illustrations, which for some of the essays is a rather critical omission. It’s apparently coming out in paperback in 2010, so kill some trees and get a version with pictures.