A place for discussion about skinning and design. Before posting questions here you should review the documentation about creating skins.
I have a customer that wants to have a page menu on the right side only some of the time. Is it possible to accomplish this without creating a separate layout.master and resulting skin?
No, it would require using a different skin on that page that has the PageMenu on the right.
You can share the css across skins by keeping it in a central location to eliminate the maintenance of duplicate css.
Hope that helps,