routes.rb

resources :categories, :constraints => { :id => /.+?/ }

## equivalent to:

get    '/categories(.:format)'          => 'categories#index',  :as => :categories
post   '/categories(.:format)'          => 'categories#create'
get    '/categories/new(.:format)'      => 'categories#new',    :as => :new_category
get    '/categories/*id/edit(.:format)' => 'categories#edit',   :as => :edit_category
get    '/categories/*id(.:format)'      => 'categories#show',   :as => :category
put    '/categories/*id(.:format)'      => 'categories#update'
delete '/categories/*id(.:format)'      => 'categories#destroy'