Would recommend using a dedicated repository. Can then give eager people commit access easily, and let them (help) manage contributions of more drive-by nature.

Would recommend using a dedicated repository. Can then give eager people commit access easily, and let them (help) manage contributions of more drive-by nature. For this to work, contrib must be possible out-of-build/tree, which is a good thing, because it means there can be other "contrib" repositories as well - not just the single special directory in the mainline repo.