nested resources multiple levels deep

I'm wondering how or if it is possible to nest a resource more than
one level.

routes.rb

map.namespace :blog do |blog|
  blog.resources :channels, :has_many => :articles
end

For example, how could I say that would like each article to have
nested comments.

map.namespace :blog do |blog|
  blog.resources :channels, :has_many
=> :articles ?? :has_many :comments
end

I'm thinking the url would look something like:
/blog/channel/1/article/1/comment/1

Thanks,

resident moron

There is another way of doing :has_many that is this way:

map.resources :posts do |post|
   post.resources :comments
end

This way your route will be something like this:

map.namespace :blog do |blog|
   map.resources :channels do |channel|
     channel.resources :articles do |article|
       article.resources :comments
     end
   end
end