A selection of Chapter 28 of the Son of Neptune at a pre-release party on Saturday. The transcript can be found
here on MortalNet's forums.
There are also minor spoilers floating around on tumblr and the Camp Half-Blood wiki, so beware! Unless you're weak willed at the last minute like me, then it's all fun and games.
I'll be turning comment notification off on this post sometime tonight. If you have the book already, please wait until tomorrow to post comments with spoilers and if you are posting spoilers, please warn as much as possible.
eta: If you have a Kindle, copies of SoN are downloading early. Of course, I have a fucking Nook.