Rails - Mar 2006 - Multiple actions for one route (making pretty URLs hit different actions)

Hi all,

I''m trying to make pretty URLs using routes for some of my actions 
across different controllers. For example:

http://www.example.com/london -> 
http://www.example.com/articles/show_by_name/london

But if the id ''about'' couldn''t be found, then to
search for it as
another action, this time from the ''branch'' controller.

http://www.example.com/london -> 
http://www.example.com/branches/show_by_name/london

And so on, checking through different actions in different controllers, 
until it finds something that matches.

How can I achieve this, preferably without building a specific 
controller/action to handle and forward requests to the appropriate pages?

Thanks a lot!

Tom