It is the new feature that Google added to Google Docs, that allows uploading folders and files. This new option works in Google Chrome, and uses the new drag and drop interface. It is very easy. Just go to Google Documents and click on the Upload button. A drop down menu will appear and the option Folder in it, therefore you can upload entire folders without selecting each individual file. It is a great way and a great place to keep the important documents online. You go, Google:)