Aeraj has been working hard on Places reference documentation. While it’s still a work in progress, it’s coming along very nicely, and I’m quite pleased with his work so far. Please feel free to give it a look and do edits if you see anything that’s busted.
Places is one of those technologies that sounds like something that won’t make any difference in your life at all — until you actually start using it and realize that it really is better than the way things used to be. I’m really enjoying the changes to how bookmarks (and the super-cool URL bar) work.