The Quest for Origins by K R Howe

A good overview of what the current opinions are on the way the Polynesians colonized the Pacific Ocean. Howe also covers historical and alternative (i.e. crazy) opinions on the same topic. The book is an easy and short read, and packs a lot of information in there. There's a little bit of a New Zealand focus (probably as Howe is a New Zealander, plus he mentions it as especially interesting in that it's the most recently inhabited piece of the world).