There is ::booboo, a collection of random ebuilds for Gentoo.

Contributors are encouraged to sign their commits. A signature from me (4E10 5CB0 7913 170D 350D  9F44 C1FD 9099 80E9 3558) denotes that I have reviewed all the previous changesets (though that might not be the case for other people: I've encountered different interpretations of the commit signatures, so it looks like they should be accompanied with the policy, like this one).