Nested resources routes

Hi!
I've got a quick question in routing.
Is there any difference between

map.resources :stuff, :has_many => :inner_stuff

AND

map.resources :stuff do |stuff|
  stuff.resources :inner_stuff
end

?

Both calls seem to do the same thing - they just register the
:inner_stuff as a resource inside :stuff resource (in terms of routes).
Do they?

Thanks