One website that we are building uses the alphatoolbar plugin. One problem that we had was that the Tag function would conduct a search of the site using the "any" searchword option. Obviously some keywords returned thousands of results while we were looking for "exact" matches, so that it functioned more like a tag system.
To change the behavior of the tag button, open alphatoolbar.php and around line 142 change :
From:
To:
