Philipp Lenssen who writes one of my favourite blogs, Google Blogscoped, has released his book "55 Ways to Have Fun with Google" as a free download in the PDF format. It’s also CC-licensed so you can "copy, read, share, remix, convert, quote, browse, and print the PDF to your liking".
You can also buy a printed copy of the book for $17. I think it’s pretty genius to release a whole book for free on the internet. If there was no free release, I wouldn’t be blogging about it right now and neither would many other bloggers. Thus more people actually end up buying the book. Mark Pilgrim did the same thing with Dive into Python and to my knowledge that was also a fantastic success.
I’ve just glanced at the book and skimmed a couple of chapters and it looks pretty interesting. There is a full chapter list at the book site. It seems to cover quite a wide range of cool tricks and cool Google-related stuff.
It’s well worth downloading a copy and if you aren’t a big fan of reading off the screen, it’s worth printing it out or buying the book. Even if you buy the book, the pdf is pretty useful as it can be searched and if you wish to quote from it, it’s just a copy and paste operation.