# File lib/taggable.rb, line 300
        def replace_tag(old_tag,new_tag,options = {})

          options = { :any => old_tag ,:separator => ' ', :conditions => nil }.merge(options)
          find_tagged_with(options).each do |item|
            item.tag_remove(old_tag)
            item.tag(new_tag, :separator => options[:separator])
          end
        end