And, about your former point: Our git format-patch policy for patches ensures that the name of the actual contributor who committed the code shows up on the commit message when doing git log. However, I think it will be useful to see which committer committed that patch on behalf of the contributor. That's exactly the problem "--sign-off" solves.
Linux kernel<http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/SubmittingPatches?id=HEAD>, for example, has a policy to use --sign-off flag and the same applies to contributing to the git project<http://git.kernel.org/cgit/git/git.git/tree/Documentation/SubmittingPatches?id=HEAD> . And, there are some other benefits too, listed here: http://stackoverflow.com/questions/1962094/what-is-the-sign-off-feature-in-git-for Mark
