gistfile1.rb

class User
  def initialize(attrs = {})
    # do stuff here
  end

  def self.find_request(id)
    request = Typhoeus::Request.new(:method => :get, 
                                    :host   => "localhost:3000", 
                                    :path   => "/users/#{id}")
    request.on_complete do |response|
      new JSON.parse(response.body)
    end    
  end
end

# Comment model looks pretty much the same

hydra = Typhoeus::Hydra.new(20) # number is the size of the easy object pool
 
user_request = User.find_request(1) # where 1 is the id of the user
user_request.after_complete do |user|
  comment_requests = user.comment_ids.map {|id| Comment.find_request(id)}
  comment_requests.each do |comment_request|
    comment_request.after_complete do |comment|
      user.comments << comment
    end
    hydra.queue << comment_request
  end
end

hydra.queue << user_request
hydra.run
user_request.handled_response # this is the parsed user object with the comments set