repository layout admin help

At the risk of sounding like a complete idiot... I am administrating a
repository (project) that has a lot of sub-projects. Is it possible to
have something like a "symlink" to these sub projects, which may
physically live in a different repository?

Here's an example layout:

MasterProject/
  trunk/
    Accounting/
      ChildProject1/
      ChildProject2/
    DesignDocs/
    Engineering/
      ChildProject3/
      ChildProject4/

Is it possible to have all the ChildProjectX refer to a separate
repository? I.e., I would like to have the following repositories:

MasterProject
ChildProject1
ChildProject2
ChildProject3
ChildProject4

So, instead of making revisions to ChildProject2, and then copy the
changes to MasterProject, I want to be able to just submit my revision
to ChildProject2, and when I access it from MasterProject, it simply
"references" ChildProject2...

My first instinct is to use a hook-script for the ChildProjects, so
whenever a new revision is committed, I'd use something like 'svn cp'
and 'svn ci' to automatically commit a new revision for the
MasterProject.

Is there a cleaner solution?

-- 
Josh Kuo <josh.kuo@prioritynetworks.net>