[wp-hackers] Adding "post_tags" functionality from backend to frontend of WordPress - to achieve "community tagging"

[Brian Layman]

 > Would be nice with the "suggested tags" but they are not life-saving 
necessary right now.

The if you are talking about how it suggests tags from a partial match 
with what you've typed, that's just add-on javascript with an ajax call 
back to the site.  Open up Firebug and watch what it does.  It would be 
easy for you to include that JS in your plugin/theme.  The official name 
of that feature is "Ajax Tag Search" and it is in 
admin-ajax_ajax-tag-search.diff

-Brian