polls_controller.rb

def multi
  poll_ids = params[:id].split(',')
  @polls = Poll.find(:all, :conditions => {:id => poll_ids})
  json = @polls.to_json(:include => {:contest => {}, :pollster => {}, :scores => {:include => :candidate}})
  json = params[:callback] ? params[:callback] + '(' + json + ')' : json

  respond_to do |format|
    format.json { render :json =>  json }
  end 
end