I just wanted to highlight a recent eBay tech blob on how Akka and Zookeeper were used on one of the eBay projects. I personally like the Actor model of concurrency (I did a short post on it once before) so just wanted to highlight the article.
http://www.ebaytechblog.com/2012/09/13/grid-computing-with-fault-tolerant-actors-and-zookeeper/
Occasional personal opinions on things
Alan Kent's Blog 