I am sure you are all well aware that I am an active member of Goodreads aka GR. I have my own GR group called Everyone's Choice. Please feel free to join in on the discussions and/or simply create your own. There we do Book Challenges of all sorts. If you have tried it yet, I highly recommend it. I have use Shelfari and LibraryThing but GR is better by far.
I have also won 9 books from the site so far. They have the contests that you enter and what you have to do, besides enter, is put it in a folder (or bookshelf) and name it First Reads and by entering in the contest you are required to post your review as soon as you finish it. The more you do this the more you win. It is a great way to spread the word of new books and also it is great for the authors and publishing companies to hear reviews before the are officially released to the public. I love to see which books I win. They are so random! Here is a list of what I've won thus far
1- Hummingbirds: A Novel by Joshua Gaylord
2- Eating Animals by Jonathan Safon Foer
3- Courage of Fear by Barbara Foyer
4- Paulo Coelho: A Warrior's Life - The Authorized Biography by Fernando Morais
5- Truly, Madly by Heather Webber
6- Sleep No More by Susan Crandall
7- The Crossing Places by Elly Griffiths
8- The River in Winter by Matt Dean (to be read)
9- Heavy Metal Pulp: Pleasure Model: Netherworld Book One by Christopher Rowley (to be read)
I always mark them ARC's (even if they are not) when I review them here so that people now that it may not be released yet.
I hope this helps and I hope you join my group. It is very comfy and cozy!