http://trak3r.blogspot.com/2009/05/better-progress-meter-for-your-rails.html

gistfile1.rb

class Progress  
  require 'action_view/helpers/date_helper'  
  include ActionView::Helpers::DateHelper  
    
  def initialize(total, interval = 10)  
    @total = total  
    @interval = interval  
    @count = 0  
    @start = Time.now  
  end  
    
  def tick  
    @count += 1  
    if 0 == @count % @interval  
      sofar = Time.now  
      elapsed = sofar - @start  
      puts "been running for #{distance_of_time_in_words(@start, sofar)}"  
      rate = elapsed / @count  
      puts "at a rate of #{distance_of_time_in_words(sofar, (sofar - rate), true)} per item"  
      finish = sofar + ((@total * rate) - elapsed)  
      puts "should finish around #{distance_of_time_in_words(sofar, finish)}"  
    end  
  end  
end  

namespace :videos do  
  desc "Remove videos from SpumCo if YouTube also removed them"  
  task :purge => :environment do  
    videos = Video.find(:all, :order => 'created_at asc')  
    progress = Progress.new(videos.size)  
    videos.each do |video|  
      progress.tick  
      video.destroy unless video.still_on_youtube?          
    end  
  end  
end