Some of the engineers from Ooyala have released a new project that “makes code reviews fun.” It is a standalone piece of software that you host on your own (they recommend using Vagrant/VirtualBox).
With barkeep you get syntax-highlighted colored diffs, the ability to easily add your own features, a simple CLI, a REST API and plaintext (threadable) emails. Out of the box, barkeep offers many more features that will keep code reviews quick and entertaining. You can use barkeep with any git repo that has a reachable URL.
The team at Ooyala plans on growing barkeep as the community sees fit. Open issues as you play around with it – better yet, fork it and add new features yourself! Their style guidelines are simple: “mimic the style around you.”