Per a request over at daria.be, I whipped up a quick WordPress plugin and am making it available for download. It places the one.org
banner in the upper right of your blog and provides a link to their
site. All you have to do is drop the oneorg.php file into your
/wp-content/plugins/ subdirectory and activate the plugin within your
Dashboard. It also work on the WordPress Multiuser platform if you make
plugins optional for your end users.
Hope this helps,