Rick Riordan said in his blog on June 1, 2010:
“Right now, there are only “locked” sample chapters from The Lost Hero. Bronze coin keychains, like the symbol above, were given out at BEA (Book Expo America ) with the pass code, and for the present, that’s the only way to unlock the chapters. If you weren’t at BEA, or can’t find someone who got the coin, don’t worry! In a few weeks, we’ll open the sample chapters for everyone.”
Well, guess what, you didn’t have to find someone with a keychain, that someone found you! Thanks to Joe who gave us this terrific bit of information in a comment a few days later…here is what Joe said: “if you go to camphalfblood.com  the password is newhero you can read the first two chapters… cant wait”.
I tried it, it worked. 47 pages worth! I couldn’t help it, I read the last sentence in the second chapter. I know, I know, bad habit, I shouldn’t have done that…but oh, wait until you read that last sentence! No! Don’t start there like I did! You’ll ruin it!
Thanks again to Joe! What a great way to start the summer.
The book comes out on October 12, 2010.
Now I’m going to go read the rest…