file_organizer.rb

class FileOrganizer

  def initialize(roots, home, debug=false)
    @roots = roots
    @home  = home
    @debug = debug
  end

  def organize_by_class_lineage(klass, current_path, lineage=[])
    if @roots.include? klass
      new_dir  = File.join(@home, *lineage[0...-1])
      new_path = File.join(new_dir, File.basename(current_path))
      mkdir_p  new_dir
      mv       current_path, new_path
    else
      organize_by_class_lineage(klass.superclass, current_path, lineage.unshift(klass.to_s.underscore))
    end
  end
  
  protected
  
  def mkdir_p(path)
    @debug ? puts(" mkdir -p #{path}") : `mkdir -p #{path}`
  end
  
  def mv(a,b)
    @debug ? puts(" mv #{a} -> #{b}") : `mv #{a} #{b}`
  end
  
end

if $0 == __FILE__
  
  # Organize all models by their class lineage

  organizer = FileOrganizer.new([ActiveRecord::Base, ActiveRecord::BaseWithoutTable, Object], "#{Rails.root}/app/models", true)

  for path in Dir["#{Rails.root}/app/models/**/*"]
    next unless File.basename(path) =~ /(.*).rb$/
    begin    
      puts "Doing: #{model = $1.camelcase}"
      organizer.organize_by_class_lineage(eval(model), path) 
    rescue LoadError => e
      puts "LOAD ERROR: #{path}"
    end
  end

end

Sample Output

Doing: BitlyProvider
 mkdir -p /Users/mikewadhera/code/involver-rails/app/models/short_url_provider
 mv /Users/mikewadhera/code/involver-rails/app/models/url_providers/bitly_provider.rb -> /Users/mikewadhera/code/involver-rails/app/models/short_url_provider/bitly_provider.rb
Doing: ShortUrlProvider
 mkdir -p /Users/mikewadhera/code/involver-rails/app/models
 mv /Users/mikewadhera/code/involver-rails/app/models/url_providers/short_url_provider.rb -> /Users/mikewadhera/code/involver-rails/app/models/short_url_provider.rb
Doing: User
 mkdir -p /Users/mikewadhera/code/involver-rails/app/models
 mv /Users/mikewadhera/code/involver-rails/app/models/user.rb -> /Users/mikewadhera/code/involver-rails/app/models/user.rb
Doing: UserError
 mkdir -p /Users/mikewadhera/code/involver-rails/app/models
 mv /Users/mikewadhera/code/involver-rails/app/models/user_error.rb -> /Users/mikewadhera/code/involver-rails/app/models/user_error.rb
Doing: UserProfile
 mkdir -p /Users/mikewadhera/code/involver-rails/app/models
 mv /Users/mikewadhera/code/involver-rails/app/models/user_profile.rb -> /Users/mikewadhera/code/involver-rails/app/models/user_profile.rb
Doing: Version
 mkdir -p /Users/mikewadhera/code/involver-rails/app/models
 mv /Users/mikewadhera/code/involver-rails/app/models/version.rb -> /Users/mikewadhera/code/involver-rails/app/models/version.rb
Doing: Video
 mkdir -p /Users/mikewadhera/code/involver-rails/app/models
 mv /Users/mikewadhera/code/involver-rails/app/models/video.rb -> /Users/mikewadhera/code/involver-rails/app/models/video.rb
Doing: VideoEncoding
 mkdir -p /Users/mikewadhera/code/involver-rails/app/models
 mv /Users/mikewadhera/code/involver-rails/app/models/video_encoding.rb -> /Users/mikewadhera/code/involver-rails/app/models/video_encoding.rb
Doing: VideoThumbnail
 mkdir -p /Users/mikewadhera/code/involver-rails/app/models/image
 mv /Users/mikewadhera/code/involver-rails/app/models/video_thumbnail.rb -> /Users/mikewadhera/code/involver-rails/app/models/image/video_thumbnail.rb
Doing: VideoUpload
 mkdir -p /Users/mikewadhera/code/involver-rails/app/models/file_upload
 mv /Users/mikewadhera/code/involver-rails/app/models/video_upload.rb -> /Users/mikewadhera/code/involver-rails/app/models/file_upload/video_upload.rb
Doing: ViewerUser
 mkdir -p /Users/mikewadhera/code/involver-rails/app/models/user
 mv /Users/mikewadhera/code/involver-rails/app/models/viewer_user.rb -> /Users/mikewadhera/code/involver-rails/app/models/user/viewer_user.rb