How to handle plugin dependency

I am trying to use the permalink_fu plugin together with the acts_as_taggable plugin so my tags will have both a full name (like COM/OLE) and a permalink suitable for use in a url (like com-ole) so I can have urls like /article/list/com-ole.

The only snag I have hit is that when I add:

has_permalink :name

to the Tag class definition I get a "method missing" error.

I was able to get it to work by adding:

extend PermalinkFu

to the Tag class defnition and also putting a copy of permalink_fu.rb in the acts_as_taggable/lib directory.

Is there a better way to do this?

I tried adding:

require 'permalink_fu'

to tag.rb but this didn't seem to help.