Exciting news! The OCWS Admin Bar Message Plugin has been accepted as an official plugin at Wordpress.org. You can see the plugin on their website at this link:
You can still download the plugin from this site, and install it by uploading it through the control panel to your site. However, you now have the additional option of searching for the plugin through the Plugins' menu and installing it direct, as with other Wordpress.org registered plugins. If you install by this latter method, you also have the advantage that whenever I update the plugin, you will get automatic notification to upgrade your plugin, which you will be able to do by a simple mouse-click.
If you want to download the plugin from this site, you can do so here.