A few days ago I submitted a contribution to mvccontrib, and it got committed.
What I added was two new ActionResults. PermanentRedirectResult and PermanentRedirectToActionResult. I've had to code the same basic thing for several different projects already, I figured it was time to stop repeating myself.
This was my first use of git. I have a bit to learn, as I am not used to thinking about source control in the way that git forces you to think, but I'll figure it out. Turns out there are a few UI bugs on github in IE 8. I had to use firefox in order to submit a pull request to get my code included into the main project.