The book looks pretty interesting from what I browsed when I got it a few minutes ago, so I actually recommend it at least as a quick reference for some pretty useful CSS techniques.
What do you have to do to get it? This is where it gets interesting:
I’m quite a fan of Twitter (you can follow me if you want), so I really like the idea. If you’re worried about your “stats”, don’t: @sitepointdotcom will follow you back 😛 And if you’re worried about spam, you can always stop following the account with a single click 😉