Thought some of you may be interested in this program. I just downloaded it today, and it's pretty slick.! The latest version is shareware, with a 30 day expiration. You can also download an older version that is freeware. You will also have to get a vrml viewer, and there are links on the site to freeware versions. This may be handy for doing interior layouts, as you will get a complete walkthru to visualize before you build. The newest version has an object builder that will allow you to build and save your own components.
Hope you find it useful!