@nyanide@lab.nyanide.com I mirror SBo using git. My package management functions are basically some ease-of-life around the core of:

# As normal user:
cat *.info slack-desc README # read about the package
. *.info # source its metadata
wget -c $DOWNLOAD # download the source
md5sum filename.tar.gz # check-sum the downloaded file
echo $MD5SUM # compare to the expected value.
fakeroot sh *.SlackBuild # build the package.

# As root:
updatepkg --install-new /tmp/*_SBo.t?z # install the built package.
chown root:root /tmp/*_SBo.tgz # make it owned by root
mv /tmp/*_SBo.tgz /var/cache/packages/slackbuilds/ # store it in my package store.
I also share the pre-built packages between my machines in general, by mirroring them to one of my servers, and downloading them to other machines from there.