I've just finished another step for new Gammu manual - it includes also documentation for gammu utility. It includes all content from the man page, reformatted and improved in some sections. So now the documentation does cover all important parts and can contain correct cross references.
The only problematic thing was to handle non dash starting commands in Sphinx. Unfortunately it does not seem to like this idea, so I had to invent some ugly hacks, which workaround that (just changing the regexps which sphinx.domains.std uses).
The man page will be from now on generated from this source as well.