My Heroku Asset Packager setup

gistfile1.txt

# Gemfile
gem 'jammit-s3', :git => 'git://github.com/meskyanichi/jammit-s3.git'

# config/assets.yml
s3_bucket: mybucket
s3_access_key_id: <%= ENV['AWS_ACCESS_KEY_ID'] %>
s3_secret_access_key: <%= ENV['AWS_SECRET_ACCESS_KEY'] %>
s3_permission: public_read
embed_assets: on

javascripts:
  workspace:
    - public/javascripts/jquery.js
    - public/javascripts/rails.js
    - public/javascripts/faye.js
    - public/javascripts/live.js

stylesheets:
  login:
    - public/stylesheets/login.css
  workspace:
    - public/stylesheets/application.css
    - public/stylesheets/live.css

# config/compass.rb
project_type = :rails
project_path = Compass::AppIntegration::Rails.root

http_path    = '/'
css_dir      = 'public/stylesheets'
sass_dir     = 'app/stylesheets'

# config/environments/production.rb
config.action_controller.asset_host = 'd5k075s055b9w.cloudfront.net'

# app/views/layouts/application.html/haml
= include_javascripts :workspace
= include_stylesheets :workspace

# config/initializers/carrierwave.rb (not asset related, but still S3 file storage)
CarrierWave.configure do |config|
  config.fog_credentials = {
    :provider               => 'AWS',
    :aws_access_key_id      => ENV['AWS_ACCESS_KEY_ID'],
    :aws_secret_access_key  => ENV['AWS_SECRET_ACCESS_KEY']
  }
  config.fog_directory  = 'mybucket'
  config.fog_host       = 'http://d5k075s055b9w.cloudfront.net'
end

# lib/tasks/heroku.rake
namespace :heroku do

  desc 'Deploy application to heroku.'
  task :deploy do
    Thread.new do
      Rake::Task['heroku:compile'].execute
      Rake::Task['heroku:jammit'].execute
    end

    puts "Deploying application (current branch) to Heroku..\n\n"
    system('git push heroku +HEAD:master')
  end

  desc 'Packages all assets and pushes to Amazon S3.'
  task :jammit => :compile do
    puts 'Packaging assets and pushing them to Amazon S3..'
    system('bundle exec jammit-s3')
  end

  desc 'Compiles all SCSS and SASS files with Compass.'
  task :compile do
    puts 'Compiling SCSS and SASS with Compass..'
    system('bundle exec compass compile')
  end

end