Find related tags with acts_as_taggable

Using the acts_as_taggable plugin, how can I go about finding related
tags? ie specify a tag, find objects that have that tag, and then count
up its other tags and return say, the top 50 or something, in a method
something like Tag.find_related_tags(tag_object)

I think the gem has a method like this but the gem hasn’t been updated
if I’m not mistaken doesn’t use polymorphic associations like the plugin
does. However how to accomplish this by modifying the plugin has eluded
me. Any ideas? Perhaps there are other plugins for tagging that have
more functions?

Gonna try to bump this one. Still can’t figure it out.