You probably want to use a bare repository (git init --bare) rather than `git config receive.denyCurrentBranch updateInstead`, which will cause your pushes to fail if you edit anything locally in the checkout. For http://canonical.org/~kragen/sw/dev3/ I run a pull from the post-update hook of http://canonical.org/~kragen/sw/dev3.git, http://canonical.org/~kragen/sw/dev3.git/hooks/post-update, which is short enough that I'll just include it here:

    #!/bin/sh
    set -e

    echo -n 'updating... '
    git update-server-info
    echo 'done. going to dev3'
    cd /home/kragen/public_html/sw/dev3
    echo -n 'pulling... '
    env -u GIT_DIR git pull
    echo -n 'updating... '
    env -u GIT_DIR git update-server-info
    echo 'done.'

You can of course also run a local site generator here as well, although for dev3 I took a lighter-weight approach — I just checked in the HEADER.html file that Apache FancyIndexing defaults to including above the file directory listing and tweaked some content-types in the .htaccess file.

This could still fail to update the checkout if it has local changes, but only if they create a merge conflict, and it won't fail to update the bare repo, which is probably what your other checkouts are cloned from and therefore where they'll be pulling from.