Often during the holidays people begin to think about updating their home, their furniture, or just rearranging. MyFourWalls (U.S. $29.99) for Mac may be just the ticket to help you visualize those changes. The app contains some intuitive tools to set your exterior and interior walls in place, elect carpeting and ceiling material, then start to populate your room with chairs, couches, tables, bookshelves etc. until you have the room built. There's everything from Flat Screen TVs to component shelves, office furniture, and kitchen equipment. You drag what you want into the room, and size it accurately with the handy guides. Once your things are in, their dimensions can be adjusted. Thinking about a new lamp. MyFourWalls let's you insert a lamp or lighting fixtures, and see the effect in the room.
Views can be overhead 2D or a very nice 3D rendering, and you can move wherever you want to really get an idea how the room will look. I could duplicate my family room quite easily, and adjustments were easy. If you get stuck, there is a handy and complete help guide just a click away.