I'm a volunteer with OpenHatch, which egor83 mentions below -- a non-profit to help people get involved in open source. At our Open Source Comes to Campus events, we aim to find great projects to connect newcomers with. (More info on the event series here -- http://campus.openhatch.org/ )
Your question struck a chord with me, since I think your curriculum and the curriculum we use for our weekend-long events would have some overlap: https://openhatch.org/wiki/Open_Source_Comes_to_Campus/Curri...
But the hard part is helping find great open source projects to contribute to.
To help with that, we wrote a guide for projects: http://opensource-events.com/
and are trying to reach out to project maintainers to help projects become "OpenHatch affiliated"; https://openhatch.org/wiki/OpenHatch_affiliated_projects -- maybe one great next step is to take this list of goals for projects, and work together in reaching out to projects to become OpenHatch Affiliated. Then you can have your students join the collection of people reaching out to those projects.
We find that having a specific person in the project care about the newcomer experience matters more than what we could find algorithmically. We still have the automated tool here: https://openhatch.org/search/ , in case you're interested.
Semi-sorry that this is a long comment, but I wanted to fill you in on a bunch of things, and I'm about to go to bed, so this has a higher chance than usual of being rambly.
OpenHatch-y people who care about outreach like this convene on the "Events" mailing list <http://lists.openhatch.org/mailman/listinfo/events/> and I hope you'll join us there and say hi! And/or reply with your thoughts here.
I'd love to collaborate on this, as it's something that we're always interested in improving for our students, too. I'm based in SF, in case you want to meet up for coffee etc.