user = User.new(:login => "bruce")
user.password = user.password_confirmation = "wayne"
user.save
blog = Blog.new(:author => user, :title => "bruce's blog")
blog.save
20.times do |i|
  blog.posts.create :author => user, :title => "posting #{i}", :content => "content"
end

collection = blog.posts
collection.paginate 3