acts_as_attachment with more than 1 image per model

Each attachment is one image. Use a has_many association for multiple
attachments:

class PhotoAlbum < AR::Base
  has_many :photos
end

class Photo < AR::Base
  acts_as_attachment
  belongs_to :photo_album
end

You can upload as many photos as you want. Check out how Mephisto does it:

http://demo.mephistoblog.com/admin/assets/new (admin/admin to log in
to the demo)

http://svn.techno-weenie.net/projects/mephisto/trunk/app/controllers/admin/assets_controller.rb