Slaying dragons with git, bash, and ruby - Ruby Pond
An often over-looked feature when using git are the various hooks you have available. They cover pre-applypatch, post-update, and anything between or beyond. I suspect a lot of people may have first been introduced to them when integrating with a Continuous Integration server as a means of telling it to test a new build, but they work equally well as a hidden monkey saving your from showing the world some of your more embarrassing mistakes.
