Rails - Apr 2009 - How to create associations with Factory Girl?

I watched the RailsCasts episode on factory_girl, and I''m trying to
get out of fixtures.

* Does anybody know an open source project that uses many of the
factory_girls features?

I came up with a pseudo code for possibly showing some association
features I don''t understand yet.

Here''s the code. It''s blog posts with comments plus tagging:
############################ CODE STARTS
create_table "posts", :force => true do |t|
 t.string  "title"
 t.text    "content"
end

create_table "comments", :force => true do |t|
 t.ingeter "post_id"
 t.string   "content"
end
create_table "tagging", :force => true do |t|
 t.integer  "tag_id"
 t.integer  "post_id"
end

create_table "tags", :force => true do |t|
 t.string   "name"
end

########################################
class Post
 has_many :comments
 has_many :tags
 has_many :tags, :through => :tagging
end

class Tags
 has_many :posts
 has_many :posts, :through => :tagging
end

class Tagging
 belongs_to :post
 belongs_to :tag
end
#########################################

Factory.define :post do |p|
 p.title ''On Girls''
 p.content ''bar foo''
 # Do I need p.association? But how can I connect
end

Factory.define :tag do |t|
 t.name ''Ruby''
end

Factory.define :tagging do |tagging|
 # What am I going to do here?
end
Factory.define :comment do |c|
 c.conent ''foo bar''
 c.association :post, :factory => :post
end
#################################### END OF CODE
I tried in many ways, but I''m not getting how to deal with
associations.
Can anybody help filling in code?

John Hunt