Go to http://www.google.com.vn/intl/en/options/
to download Google Sketchup for free. Google Sketchup is a free programme designed and created by Google, and you can draw, design, do artworks of architecture with this new programme. Click on Sketchup to download, which is in the Communicate, show & share section of the page. It's a large file to download, so you would have to wait for it while it downloads the file, which takes about 30 minutes. So, just giggle around and come back in a half hour!