Google SketchUp is the 3D modeling tool for design beginners.
* Using SketchUp (free), you can:
- Draw, modify, measure, rotate, scale, and move geometry.
- Use accurate dimensions, and communicate them with text tools.
- Place section slices to view and work on model interiors.
- Add pre-made textures like brick, wood, shingles and glass to your models, or create new textures.
- Add pre-made components like trees, cars, doors and windows, and people to your models, or create new components.
- Soften and smooth faces.
- Cast real-time shadows for any location on earth.
- Simulate movie camera placements.
- Perform walk-throughs.
- Create presentation tours.
- Use organic modeling (Sandbox).

* Import 2D images:
- JPEG image (.jpg)
- Portable Network Graphics (.png)
- Tagged Image File (.tif)
- Targa File (*.tga)
- Windows Bitmap (.bmp)

* Import 3D models and information:
- SketchUp (.skp).
- Google Earth terrain. Note: You can get the current image-in black and white snapshot-of the terrain image currently displayed in Google Earth by clicking the "Get Current View" button.
- Two versions of the terrain image are imported: 2D and 3D, and you can toggle between them by clicking the "Toggle Terrain" button. The terrain images are for reference only, and are not included when you place your model in Google Earth. The image includes a reference to the latitude and longitude of the location in Google Earth, so it can be used for shadow studies, as well. Google Earth doesn't export its own 3D buildings (the buildings that are displayed when you select the "Building" layer in Google Earth). That information is licensed and can't be redistributed, so you can't import those buildings into SketchUp.
- 3DS (.3ds). Note: If you want a 3DS import to include textures, before the import you must save the texture files in the same folder as the 3ds file itself.
- ACAD (.dwg, .dxf)
- DEM (.dem, .ddf)

* Export 2D images of your models:
- JPEG image (.jpg)
- Portable Network Graphics (.png)
- Tagged Image File (.tif)
- Windows Bitmap (.bmp).

* Export animations and walk-throughs as MOV or AVI files.

* Place models in Google Earth. You can place SketchUp models in Google Earth by using the "Place Model" command. Google SketchUp automatically determines the version of Google Earth you are running (3 or 4) and creates the appropriate .kmz file. (The new versions of
Google SketchUp and Google Earth now support displaying textures and images in Google Earth.)

* Export a Google Earth file directly in KMZ (Google Earth 3 or 4) format. Google Earth 3 files can be viewed in either version of Google Earth, but textures are displayed only in Google Earth 4. Google Earth 4 files can't be viewed in Google Earth 3.

* Share SketchUp models to the 3D Warehouse. For models that have a location in Google Earth, the upload creates both a SketchUp (.skp) and Google Earth 3 (.kmz) file. If you have the new version of Google SketchUp (downloaded on or after June 12, 2006), the upload also creates a Google Earth 4 (.kmz) file.

* Print the portion of your model that is displayed in the SketchUp drawing window.

* Print and export raster images at a resolution you choose.

* Create add-on programs using the Ruby programming language.

Google SketchUp Pro is the 3D modeling tool for design professionals
The professional version of Google SketchUp empowers design professionals to explore and communicate complex design concepts. SketchUp Pro includes additional design and presentation tools, LayOut and Style Builder. Also, SketchUp Pro offers the following features:

* Export in additional 2D formats:
- Portable Document Format (.pdf)
- Encapsulated PostScript Format (.eps)
- Epix (.epx)
- AutoCAD (.dwg, .dxf)

* Export 3D models in additional formats:
- 3DS (.3ds)
- AutoCAD DWG (.dwg)
- AutoCAD DXF (.dxf)
- FBX (.fbx).
- OBJ (.obj)
- XSI (.xsi)
- VRML (.vrml)

Use many available importer and exporter plug-ins.
Receive email technical support.

I think I included it all. If I missed something feel free to mention it in this forum.