advice on has_one edition

In my model a user has one address.

The form for creation/edition of users shows plain fields for their address fields, the user does not see the split in the interface. A way to write that is

   <% @address = @user.address %>
   ... form helpers for @address ...

   in the controller you take params[:user]
   and params[:address] and construct the
   stuff by hand

Is there a more idiomatic approach?

-- fxn