I just came across this tool, called git-dude. It's a simple git plugin that lets you watch certain git repositories, and it will post a message using libnotify or growl when there are new commits or branches. It's a really basic tool, and if nothing else the shell code is really a fun read. Check it out, it's useful.

Josh Adams is a developer and architect with over eleven years of professional experience building production-quality software and managing projects. Josh is isotope|eleven's lead architect, and is responsible for overseeing architectural decisions and translating customer requirements into working software. Josh graduated from the University of Alabama at Birmingham (UAB) with Bachelor of Science degrees in both Mathematics and Philosophy. He also occasionally provides Technical Review for Apress Publishing, specifically regarding Arduino microprocessors. When he's not working, Josh enjoys spending time with his family. <a href="http://www.erlang-factory.com/conference/show/conference-6/home/"><img src="http://www.erlang-factory.com/static/upload/media/1389191028314604speaker120x125gif" alt="speaker badge" /></a>