Sweet Home 3D 1.2 – Freeware Files.com – Home & Education Category
Sweet Home 3D is a free interior design application that helps you placing your furniture on a house 2D plan, with a 3D preview. Sweet Home 3D comes with 50 pieces of furniture, but you may also import some additional objects in it.

Here’s another floorplan creator. The bonus with this one is that it’s available for Macintosh and Linux as well.