Git is a source code management system designed around the idea that branching and merging should actually work. The result is that you're likely to have many more open branches than you otherwise would using a system such as Subversion. But how can you or the rest of your team quickly get up to speed on all of your branching activity?
That's where GitHub's network graph feature comes in handy. With it, you and your team can get a detailed, graphical, interactive view like the one above (click it for the interactive version).