Routes for external targets

Is it possible (and if so, is it advisable?) to set up a named route
that has a completely external URL as a target?

I have something like this in my routes file:

map.merb_uploaded_file_create
'http://another_server/uploaded_files/create', :controller => nil

so I can then use merb_uploaded_file_create_url in my code. Is this
anything that someone has done?

Wes