GPG signing for git commit?

Hi,

It crossed my mind that currently git commits cannot actually be
verified to be authentic, due to the fact that I can just set my
identity to be someone else, and then commit under their name. During
discussion on #git, Ilari, context and I figured that it would be a good
idea to get GPG signing on git commits, considering that git-tag already
has GPG signing support.

Attached is the transcript of the log, with some irrelevant bits chopped
out. Log is dated Sat, April 4, and timezone GMT +0800.

-- 
Chow Loong Jin