Room Visualizer is nice drag-n-drop web application to help you try various color schemes, textures and carpet materials in the different areas of your house.
Just choose from a wide array of materials or colors and drag them on to the flooring or the walls of your room to envision the design before you order the material from the store.
A nice tool that removes most of the guess work that's generally involved when you are remodeling or renovating your home.
Quick Tips: Use Firefox as Room Visualizers returns some script errors inside IE.
Room Visualizer [via Scott Hanselman]