nested namespaces in resources block?

Dear list,
Is it currently possible to use namespaces inside a resources block?
For example:
map.resources :projects do |projects|
  projects.resources :tasks
  projects.namespace :wiki do |wiki|
    wiki.resources :pages
This should generate URLs as "project/:project_id/wiki/
pages/:page_id". I think in this way functionality will become better
seperated and thus the app becomes better maintainable.

I know this does not work and was wondering what will. Currently I am
projects.resources :pages, :controller => "Wiki::Pages", :path_prefix
=> "/projects/:project_id/wiki", :name_prefix => "project_wiki_"

This sort of works but my RSpec tests now throw RoutingErrors,
needless to say this is also very unbecoming.

Thanks in advance,