This week's giveaway is in the EJB and other Java EE Technologies forum. We're giving away four copies of EJB 3 in Action and have Debu Panda, Reza Rahman, Ryan Cuprak, and Michael Remijan on-line! See this thread for details.
To be honest, I haven't spent a lot of time browsing different projects on Nemo. I will say that it's interesting to look at Java 7 and at SonarQube itself. It makes me feel better that there are even issues in the code quality tool.