I just released Galleon 2.2, which has a feature that folks have been asking for since 1.0. Users can now edit their own posts. This is thanks to Todd Rafferty. He did all the work for it and I just had to mod a line or two. My main objection to the ability for folks to edit messages was because I was worried folks would use it for abuse, but Todd added an automatic 'message edited' type when a user edits a message.
Anyway, enjoy.