I totally participate! I somehow wasn't so obsessed with Librarything at the time that I didn't find out about the program until it's second month. I think this was before I joined any of the Groups on Librarything and literally just used it to catalog my books.
I didn't get any books my first several months and then they started coming in one after another after another. Now I'm back to not receiving anything for 2-3 months. I don't mind at all, the program is so exciting, it's just fun belonging!
I have received 7 books so far and they are (in order, I think):
Gossip of the Starlings-Review
Secrets of the Hollywood Girls Club-Review
Loose Girl, which finally just came!-Review
I've actually also hunted down several other books that I didn't end up getting through the program because I really wanted to read them!
The Early Reviewer's Program is actually what got me to start writing reviews. It also was the first hints of my blog becoming more book related.
For the most part I've enjoyed the books I've received from the program. I actually didn't really care for my first two but since then they have all been pretty good. It would be hard to pick a favorite so I'll settle on Loose Girl and American Wife.
I totally participate in the discussions. You can find me on the Early Reviewers. Bookmooch, and ARC Junkies boards most frequently!