ARC of Original Sin, but also a signed copy of Demonglass by Rachel Hawkins! Head on over to her blog, here, to see how to enter. Good luck!
Be sure to check out Original Sin on Goodreads.
If you don't win (or even if you do), you can pre-order Original Sin at any of these bookstores:
Books A Million
Barnes & Noble
Release Date: July 5, 2011!!