I signed up to the CPAN Pull Request Challenge - apparently I'm entrant 170 of a few hundred.
Then I extended the Travis file to generate coverage reports, and separately realised the docs weren't quite fully complete, so fixed this and added a test.
Two of these have already been merged by the author, who was very responsive.
Part of me worries that Github is a centralized, proprietary platform that we now trust most of our software source code to. But activities such as this are surely a good thing - how much harder would it be to co-ordinate 300 volunteers to submit patches in a distributed fashion? I suppose you could do something similar with the list of Debian source packages and metadata about the upstream VCS, say...