rails hit three

<a href="?sort_by=title">Title</a>
def list
  sort_by=params[:sort_by]
  @book_pages,@books = paginate :books,:order => sort_by, :per_...
end
#no ajax order

#change gem to plugin
cd vendor/plugins
gem unpack acts_as_taggable
add a file named init.rb to the dir
write: require 'taggable'