Whether you are using Sketchup Pro or Free, version 6 or 7, you'll find Twilight working right inside with you.  All the editors are directly accessible from the Twilight Toolbar, and many features are easily available from one of SketchUp's context menus.  Twilight manipulates data directly from SketchUp, providing immediate access to lights, layers, scenes, and materials.  All of Twilight's data is stored right inside the SketchUp Model file, so you never lose a thing.  And sharing a scene with other users is seamless.