CMS Challenge

Hi all,

I am planning on building a website for a client using Rails and RESTful
routing. The website will be built around a content management system,
so the client can manage their own content.

So the structure of the site will look something like this to site
visitors:

http://clientsite.com/about
http://clientsite.com/portfolio
http://clientsite.com/news

However, the client will be able to login to the content management
system which will use the same routing. How should I structure the rest
of my system to accomplish this? I thought about swapping out the views
based on whether the user is visiting the website or administering the
website, but I would like the administrator to be able to see changes on
the website as they occur. If I swap out the portfolio/index view with
a portfolio/index_admin view, the administrator will not be able to see
the portfolio page unless they log out of the system.

Any ideas or recommendations?

Thanks,
Brandon