Andrew,
As I understand it you have multiple blogs that you would like to RESTify but you need another route mapping... just use REST plus one extra route like this:
map.resources :blogs map.connect 'blogs/:year/:month/:day', :year => nil, :month => nil, :day => nil, :requirements => { :year => /\d{4}/, :month => /\d{1,2}/, :day => /\d{1,2}/ }, :controller => 'blogs', :action => 'index'
Then check in index action for params. If present, add conditions to Blog.find(...) as needed. Check article_controller.rb in the mephisto source for a good example of this.
Hope this helps,